What is the TRUTH about 800-X load data?! [Archive] - Glock Talk

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21Carrier
06-28-2011, 16:56
Guys, I think we all agree 800-X is the most powerful 10mm powder out there, but the more I play with this stuff, the more it starts to bother me. What in the hell is the deal with the load data inconsistencies? Does anyone really know? Anyone that's been around 10mm reloading for even a few weeks has no doubt seen or heard about the now infamous 135gr Nosler load, but that's not what really bothers me.

What really bothers me are the inconsistencies in other weight bullets. For example, my new Hornady book says a 155gr XTP maxes out at 11.5 gr of 800-X (CCI 300, COAL 1.260" for all loads unless noted otherwise). It says that load does 1350fps, but I KNOW that's crap. Also, I see other sources maxing out BELOW 10.0gr with a 155gr bullet!!! What is the deal?!

My only guess on this matter is that 800-X has some crazy characteristics. Here's what I mean: in my testing (load workups) it seems that case expansion with 800-X increases to a point, then as you push further, it actually DECREASES for a bit, then starts rising again. To clarify, it almost seems to have a FALSE maximum that comes in early, but can be pushed through. Is this perhaps the reason some books stop so low? Maybe they are hitting the premature maximum, thinking it is max, and stopping the work-up.

I have noticed this during "in field" case measurements, but since I only tend to keep my last grain or so of worked up empty shells separate for further home measurement/inspection, I don't have hard number to back it up. I just remember hitting a case expansion figure that was near my max at a charge well below book max, but after carefully pushing on, the expansion seemed to decrease a bit then increase again. Has anyone else had similar results?

By the way, this is only based on remembered "in field" measurements and should not be taken as fact. Please don't think this is fact and push beyond pressure signs. At this point this is nothing more than a curious observation and cause for discussion.

Taterhead
06-29-2011, 09:06
You are vocalizing a sentiment that I have had for some time now about 800-X. That is why I have been migrating away from it. I have had fairly nasty symptoms of pressure in one instance at far less than book max (180 xtp), yet loaded to 14.5 grains under a 135 gr Nosler with benign pressure symptoms. Looking at burn rate charts, it is a relatively quick burning powder - to a point. This is all conjecture, but it seems to slow down with heavier charges. I imagine that there is a point where there is an inconsistent burn at higher charges (I.e. the Nos 135 data) so pressures level off or maybe decline. - I don't know. With the 135, there was no increase in velocity from 14.0 grains to 14.5 grains.

The solution to incomplete burn is traditionally to use a mag primer. However, this powder is an altogether different animal with mag primers in my experience. I don't use them with 800-X.

Ultimately for me, I can't seem to get a read on that powder. It is a strong performer overall, but I am hesitant to push it. If I am hesitant to shoot any load, then I don't. Period.

I like Accurate no. 9, and have nearly 200 test loads of Longshot with various bullets to try.

My guess with the huge cushions for pressure found in load data might have something to do with leaving a huge fudge factor for 1) poor metering of 800-X and 2) pehaps the labs are finding some wide variations too. I don't know.

MinervaDoe
06-29-2011, 09:54
Metering is about the only variable that you can take out of the equation by carefully weighing each shot in your test batches.

Other than that, this is the sort of torment that has made me swear a dozen times that I will never use this powder or that powder ever again. In the end, I always come back, but with some new rule or constraint.

If I had hair, I'd say it was enough to make my hair fall out (or get pulled out).

_The_Shadow
06-29-2011, 11:25
My take is that most 0.400" Hollow Point bullets for 10mm/40 cal. are made more for the 40S&W performance, they don't requier that much velocity to have them open up, over driving them tends to break them apart at the higher speeds. With that in mind, Self Defense type loads are taken into consideration performance wise so velocities are less, to prevent pass thru or explosive expansion.:shocked:

Manufactures are not showing the higher loading data of years past for several reasons but mostly liability reasons. They have no idea what a handloader will be putting into what casing, with what primer and shot thru a gun with no knowledge of its condition. So they revised the data to reflect a larger safety margine taking the unknowns into account. The statements like use "current data" play into their hands for this reason.

Then there are the "Velocity Jockey", "Performance Pusher" or the "Ballistician Magician" trying to squeeze every fps or ft lb from the loads...Yes there are many who chase the give me more attitude...:wow:

I too load toward the upper performance levels but look for the balance of accuracy and 100% reliability with my safety in mind!:supergrin:

Jitterbug
06-29-2011, 11:38
To try and answer one question regarding the load data, I have a note in my Hornady 7th, regarding AA#7 and the suggested weights for the 155 XTP.


7/12/10, Glocktalk, data suspect under Accurate data.

The Accurate Arms 3.4 Edition has 12.7 grains as max, for a Hornady 155 H.P., same as the Accurate Arms 3.5 Edition, showing pressure as 37,500 PSI.

I know there is a difference between the Hornady HP and XTP, but, I think taking a 155 gr. XTP up to 15.1 grains as suggested on page 861 of the Hornady 7th, might be a bit questionable and if the AA#7 data is off, well I suppose it's within the realm of possibility that all the data on that page might be off?

Without sifting back through the aforementioned Accurate Arms data, the gist of the thread, IIRC, was that Hornady made a mistake. Point being the manuals are not always gospel.

I don't get it either with 800x, guys are for the most part getting really good results, although most recommend not using 350's and some like Tater have had results which make them nervous.

I recently read an article by Elmer Keith, where he claimed one characteristic of certain smokeless powders was at a given point they detonate rather then burn, (I couldn't help think of 800-x loads) so he advocated staying within book maximums...Elmer of all people, considering the way he pushed the .44 Special for one.

I don't know much, but one thing I always do is to confirm a load in at least two well known published sources, I prefer three and can usually do that with powder online data, then I generally use the lowest and go from there, I seldom use max load data.

And I'm hesitant to go over book, I don't care what someone on the internet did, curious yes, but that doesn't mean I'm doing it.

The highest published charge weight I can find for a 200 grain bullet with 800x is 8.1 grains with an XTP in the Hornady 7th. I've seen McNett state he's used 10.0 grains and users on this forum going almost as high without mishap thus far.

I'm sticking with 8.1 grains with a 200 gr. WFNGC for now and feel a bit frisky doing that, since it's not the exact same bullet, and my other respected, published sources are recommending 7.8 and 7.6 grains as max with 200 grain bullets.

Other then that, I'll eventually be looking into other 10mm powders, L.S. is probably going to be next.

And if I need more velocity, power and weight, and I do out here in the Rocky Mountains, it will be a .44 Mag.

I love my 10mm but like all calibers it does have it's limits.

As an aside, I was out yesterday, in the hot, scorching sun, I had various, open ammo boxes, since I was wanting to put my difficult to find brass back into the same box it came from. It got extremely hot, very quickly and I had to wonder what it was doing to the powder and pressures, and I did quickly get it out of the hot sun.

On a similar note if 800x acts up with 350's, it might have other characteristics we're not familiar with, which is why the published sources have the data they do.

21Carrier
06-29-2011, 14:05
I just don't understand this powder. Most other powders seem to have similar maximums across different brand manuals, but 800-X is not so. Obviously, there are differences in quoted max loads for other powders, too, but with 800-X it's just so extreme. I just don't see why some books stop TWO GRAINS lower than others, and publish a pressure of 30,000psi. I just feel that there's something unique about this powder that makes it different than the other pistol/shotgun powders.

I also understand what Shadow is saying about not overdriving .400" bullets, but I feel that is beyond the concern of the load book writers. I don't want them to limit my data because of current bullet design. I want them to limit data to PRESSURE. Basically, I want the upper limit to be the upper limit because it's nearing 37,500psi, not because they feel I'm going to be over-driving given bullet designs.

I guess in the end Taterhead is right. I think there's a lot of sense in the idea that they are covering their butts because of 800-X's poor metering qualities. I also agree that there are some weird pressure characteristics that are limiting them.

That still doesn't explain why Hornady chooses to go so far with their 155gr 800-X load, then stay relatively safe with the 180gr and 200gr loads. It would seem (from the 180gr and 200gr loads) that Hornady is playing it safe like the others. But then they go and push the 155gr load to what I am certain is a TRUE maximum figure. So they only take the metering/pressure issues into account with the heavier bullets? THEN, there's the issue of that max 155gr XTP's velocity. It is wrong. I have no doubt, but I'll confirm it soon when I get a chronograph.

I guess the bottom line is that I'm just really interested in what's going on. I'm in no hurry to vaporize my gun and fingers, but I aim to do some serious testing as soon as I have a chronograph.

I am going to try to figure out a way to do some poor-man's pressure testing. Any other car guys out there? If so, I'm sure you've heard of Plasti-gauge. I'm wondering if a piece of Plasti-gauge wrapped around a bullet could be translated into relative pressures. I realize this would be HIGHLY unscientific, and would be nearly impossible to translate to actual psi figures, but it just MIGHT give a better idea of RELATIVE pressure, which is all we really need. If it, or something like it, would reliably show the difference in pressure between two loads, that's all I would need. Then it could be compared to a well-known max load. I may go get some this weekend. I just hope it doesn't melt or disappear into the wind upon ejection.

_The_Shadow
06-29-2011, 19:07
Here is yet another thought to ponder...FMJ, FMC, JHP, Lead Free

Each of these bullets may weigh the same but be very different in total length and space occupied within the cartridge case. This can and does affect pressure based on the powder compression or free space... same amount of powder but less space increases pressure.

Then when you think about setback issues that increase the pressures, can you see where the manufactures want even more safety cushion to distance themselves.

In the past they pushed and published higher limits to sell their products just like the Auto manufactures...Chevy vs. Ford vs. Dodge! The performance junkies eat it up and buy!

Now Carrier, about your pressure testing...I don't know if the plasti-gauge will yield any data that could be interpted but trying doesn't hurt!

Pressure test barrels (fixed and round so the strain can be wrapped) that they use a strain gauge wrapped are usually compared to know test performed. I suppose it is based on the expansion of the barrel metal acting on the strain gauge...repeatable and instant read out as a graph over time via computer.

I think he old C.U.P. method was probably more precise based on the crushed copper disk of known compressive forces. This was slow and could only be use once per disk which had to be evaluated as a maximum.

I would like to see a chamber cut (slightly oversize near the rear) so as to have the strain gauge wrapped around the cartridge of test and slid into the test chamber. This would be directly acted upon the gauge. This may show different for specific brass cases.

But what do I know! Absolutely nothing!:faint:

TDC20
06-29-2011, 23:27
Carrier, I'm glad that you started this thread, because the 800-X issue has bothered me quite a bit, also. I'm used to following published load data without question, so when I saw some of the data and the results posted on the 10mm reloading forum for 800-X, I was a bit skeptical. However, since Hodgdon's data shows the max load for 180gr bullets at 30,000 psi, there's clearly more margin there than what is published. I've cautiously loaded beyond the published level, but that always bothers me. And up to a couple of days ago, I bought into the "poor metering" line of thinking that kept Hodgdon from publishing true max pressure data. Then, I was browsing Hodgdon's on-line reloading data for 357 Sig, and I found this:

147 GR. HDY XTP, IMR 800-X, 1.140" OAL, 9.0gr 1317fps, 38,000 PSI

Which tells me that the metering issue must be bogus if they are willing to show 38,000 psi data for the 357 Sig. My guess is that 10mm Auto is too small of a market for them to spend the time and money testing for maximum pressure 10mm load data. I could be wrong about this, but the 357 Sig data kind of backs up this line of thinking. In a way, I feel hurt. :dunno:

Back to what you said about false pressure maximums, I also saw this when working with 135gr. Noslers and 800-X. At 12.3gr (using Rem 2.5 primers, LWD 6" bbl, and 22lb recoil spring) I was averaging 1667fps, but at 12.5gr. I was averaging 1661fps. I also noted a flake of unburnt powder on the magazine lips after firing the 12.5gr. load. I stopped there with my load development, as I didn't want to push any higher than that, even though case head expansion was still good and there weren't any other signs of pressure. I still don't know exactly what to make of those results, but it was enough to slow me down and I'll think about it a long time before going back there.

I'm still a big fan of 800-X, especially for "heavy and fast" loads. Until someone does some certifiable pressure testing, though, it will be a mystery as to where that 37,500 psi mark lies. Until then, I think I'll err on the side of caution.

21Carrier
06-30-2011, 02:25
The 135gr Nosler load was the one that caused me to notice these weird pressure signs. I worked up from 11.5gr to 13.0gr (CCI300, COAL 1.260"). Around 12.0gr I was getting near max expansion (my max is .435", which is usually the point where the smiles appear). I made the decision to move further and noticed expansion slightly DECREASED. By the time I got to 12.5gr, the expansion had backed down to like .433". Then it slowly increased again back up to max, and I called it quits at 13.0gr. It was just weird.

Thanks for posting that .357Sig load. That sounds like one hell of a .357Sig load!

You know, just thinking about it, there are so many factors that are just miles above our heads and means of observation. For example, this phenomenon could just be an artifact of my barrel length. Different length barrels will result in different harmonics which could produce secondary and even tertiary pressure waves. Or even the massive flakes of 800-x could cause it to be so different. Maybe more of the flakes combust halfway down the barrel. Who knows. I know it's beyond my abilities of observation without expensive equipment. I think I'll just keep shooting crap, and leave the testing to the guys that have the equipment!

Jitterbug
06-30-2011, 07:12
TD

Good find and observations on the .357 Sig data, I'm a bit startled by it. 38,000 PSI?

What if?

IMR has a link I quickly found with an email address. As you can see at the link they tout 800-x as being an excellent choice for 10mm.

http://www.imrpowder.com/hs800x.html

Gee, how about some up to date and relevant data guys? Especially with the bullets we're using?

What if all of us dedicated 10mm re loader's and 800-x fans, start an email campaign asking them to provide us with some more 10mm data, even going as far as telling them what loads we're developing and asking if they'd kindly provide feedback and support of their product?

Couldn't hurt and we might learn something?

As 21 said, without cost prohibitive equipment, we're flying by the seat of our pants here.

Taterhead
06-30-2011, 10:53
A thorough re-test of the 135 grain load would serve us well. How many believe that the max would still be at 14.5 grains? Not me. The max now for a 155 gr is IIRC 9.8 grains.

Jitterbug
06-30-2011, 11:43
I'd like to see 135 Nosler, 155, 180 and 200 grain XTP's and the 200 grain WFNGC, if they'd max those out at 37,500 psi and let us know that would be sweet.

Burien
06-30-2011, 12:59
My 800x Max load with the 135 gr Nosler is 13 gr @ 1.260" with Tula Large Pistol primers in a KKM G-29 factory lenght barrel.

My Max load with a factory Glock OEM barrel is 12 gr and all else the same, gets me right about 1495 fps and no glock smile on my brass.

Taterhead
06-30-2011, 13:53
Both 14.0 & 14.5 grains with CCI 300s (1.25") ran at 1695 fps in my stock G20 w/ 22# spring. No symptoms of excess pressure. I do not shoot them at those levels any longer. In fact, I have loaded a bunch to thoroughly re-test workups with the Nosler from 10.0 to 12.0 grains in small increments. I intend to get some additional data that I did not collect when I first did load workups several years ago. When I can get to the range (and when I am not doing other things at the range) I will post my results.

TDC20
06-30-2011, 21:21
I have a theory about what is happening with the light (135gr) bullets and 800-X. About 6 months ago, I had a half-baked idea to develop a way to shoot 22 cal air rifle pellets out of my .22 LR (I don't own an airgun now). The target was going to be starlings off the backyard bird feeder. Anyway, I pulled some bullets from some cheap 22 ammo, dumped the powder, and then loaded 1gr of the fastest powder I have on hand, which is Bullseye. The plan was to chrono the velocity and work up to about 1000fps. The only problem was that I was only able to get one out of about 10 rds to actually burn the powder and accelerate the pellet out of the barrel at a decent velocity. On the rest, only the rimfire primer burned, leaving a mess of unburnt Bullseye in the barrel. The problem is that smokeless powders burn fast under intense pressure, as can be seen by lighting a few grains of powder with no pressure. Low pressure means a slow burn. I believe the 135gr/800-X "reverse pressure work-up" is a case where there is an initial violent expansion of gasses from the primer and an incomplete initial powder burn. As the bullet moves quickly down the barrel, the pressure drops, slowing the burn rate before all the powder can be burned inside the barrel. Heavier bullets with 800-X don't have this problem, because the pressure remains high enough to complete combustion as the heavier bullet accelerates at a slower pace down the barrel, maintaining a higher pressure. It's possible that using a magnum primer might fix a theoretical 135 slow burn problem, but I'm already getting 1660 fps (6" LWD) with a standard primer, and I've had lower pressure signs with standard primers and 800-X in general, especially with heavier bullets.

Again, this is just a theory, but if it's anywhere near accurate, it could result in some very serious sudden overpressures when a seemingly benign load suddenly and unexpectedly gets a 100% burn and subsequent huge pressure spike. For that reason, I have quit loading 800-X for 135gr. bullets and instead now use Longshot for my 135's, although 12.0gr 800-X/135 with a standard primer is a safe load that I feel comfortable with in my G20. I won't go any higher than that, though.

I still think 800-X is THE 10mm high performance powder for 180 and 200 gr bullets if you can deal with hand-weighing. I haven't done enough work with 150-165gr bullets yet to have an opinion as to what works best there, but I'm leaning towards Longshot, mainly for the metering qualities. The 135/800-X situation is a squirrelly one, and I'd just as soon avoid any handloads that exhibit squirrelly behavior, especially since the original 14.5 gr. data has not been republished.

Taterhead
06-30-2011, 22:20
Again, this is just a theory, but if it's anywhere near accurate, it could result in some very serious sudden overpressures when a seemingly benign load suddenly and unexpectedly gets a 100% burn and subsequent huge pressure spike.

Good post. That is EXACTLY what I was thinking. Get a complete burn @ 14.5 grains and....

Some guys running mag primers are getting pressure symptoms in the 12.0 range like blown primers, etc. My loads with 14.5 grains (standard primers) have been benign. With velocities not increasing relative to 14.0 grains, I suspect that unburnt powder is traveling down the barrel. If it were to efficiently ignite, could be trouble with all of that powder.

21Carrier
07-01-2011, 01:26
I'll be sending an e-mail to IMR. I think it might be worthwhile for all of us to do so. I'm going to try to make them feel guilty about advising 800-X for use in 10mm, yet failing to provide good data. If you go by THEIR data, 800-X is no better than lots of other powders. It's only when you go beyond their data (and likely still within 10mm's SAAMI spec) that 800-X becomes the king of the 10mm hill. I just feel limiting 800-X to 30,000psi only in 10mm does no good for anyone. It doesn't help us be safe, because most of us will push beyond their published maximum since we see there's room to spare, and loading blind is not safe. It also certainly does not help their reputation or powder.

I will write them tonight, and also make them aware of this thread. Maybe someone with some time on their hands will pay attention.

_The_Shadow
07-01-2011, 08:17
What we may see happen in the future, is that the pressure numbers maybe absent from the data. MHO is that this would leave the handloader blind to where the loads are in any shown data...Sad if they do.

Alliant's Reloader's Guide still shows pressure data for the shotshells but no pressure data listed for the pistol or rifle...

Better start hanging on to the data guides of years past where they actually provide the proper data with pressures...Copy and paste into word files and save the electronic listed stuff also. I save my older data books for that reason as well.

Jitterbug
07-01-2011, 10:37
I'll be sending an email out as well, politely asking them to provide us with some updated data.

I think providing a link to this discussion is a good one.

Can't hurt to try.

21Carrier
07-01-2011, 13:28
What we may see happen in the future, is that the pressure numbers maybe absent from the data. MHO is that this would leave the handloader blind to where the loads are in any shown data...Sad if they do.

Alliant's Reloader's Guide still shows pressure data for the shotshells but no pressure data listed for the pistol or rifle...

Better start hanging on to the data guides of years past where they actually provide the proper data with pressures...Copy and paste into word files and save the electronic listed stuff also. I save my older data books for that reason as well.

I really hope that doesn't happen, but it wouldn't be THAT bad. As long as the maximum charges are TRUE maximums (meaning at or damn near 37,500psi), then you really don't need them to tell you. As long as max really means max, then it's a given that pressure is about 37,500psi. The problem happens when they list a max that's really only at 30,000psi, then omit the pressure data. THAT is not good. As long as their max is a true max, I'll be happy.

Obviously, if y'all have ever seen anything I do (the wax tests for instance), you know I love data, so I would RATHER have all the data possible. Hell, it would be ideal if they would provide pressure charts or graphs that would give pressure vs. time, and area under the curve. With that, we could REALLY do some learning. But I'll be satisfied if they just update the data to true maximums.

EDIT: By the way, I sent IMR an e-mail. I guess we will see what they say.

gator378
07-01-2011, 16:17
I have a theory about what is happening with the light (135gr) bullets and 800-X. About 6 months ago, I had a half-baked idea to develop a way to shoot 22 cal air rifle pellets out of my .22 LR (I don't own an airgun now). The target was going to be starlings off the backyard bird feeder. Anyway, I pulled some bullets from some cheap 22 ammo, dumped the powder, and then loaded 1gr of the fastest powder I have on hand, which is Bullseye. The plan was to chrono the velocity and work up to about 1000fps. The only problem was that I was only able to get one out of about 10 rds to actually burn the powder and accelerate the pellet out of the barrel at a decent velocity. On the rest, only the rimfire primer burned, leaving a mess of unburnt Bullseye in the barrel. The problem is that smokeless powders burn fast under intense pressure, as can be seen by lighting a few grains of powder with no pressure. Low pressure means a slow burn. I believe the 135gr/800-X "reverse pressure work-up" is a case where there is an initial violent expansion of gasses from the primer and an incomplete initial powder burn. As the bullet moves quickly down the barrel, the pressure drops, slowing the burn rate before all the powder can be burned inside the barrel. Heavier bullets with 800-X don't have this problem, because the pressure remains high enough to complete combustion as the heavier bullet accelerates at a slower pace down the barrel, maintaining a higher pressure. It's possible that using a magnum primer might fix a theoretical 135 slow burn problem, but I'm already getting 1660 fps (6" LWD) with a standard primer, and I've had lower pressure signs with standard primers and 800-X in general, especially with heavier bullets.

Again, this is just a theory, but if it's anywhere near accurate, it could result in some very serious sudden overpressures when a seemingly benign load suddenly and unexpectedly gets a 100% burn and subsequent huge pressure spike. For that reason, I have quit loading 800-X for 135gr. bullets and instead now use Longshot for my 135's, although 12.0gr 800-X/135 with a standard primer is a safe load that I feel comfortable with in my G20. I won't go any higher than that, though.

I still think 800-X is THE 10mm high performance powder for 180 and 200 gr bullets if you can deal with hand-weighing. I haven't done enough work with 150-165gr bullets yet to have an opinion as to what works best there, but I'm leaning towards Longshot, mainly for the metering qualities. The 135/800-X situation is a squirrelly one, and I'd just as soon avoid any handloads that exhibit squirrelly behavior, especially since the original 14.5 gr. data has not been republished.

After reading these tales of woe, I will stick with Acurate #9. Almost as fast in the velocity department, but goes bang everytime without problems and meters perfectly everytime.

21Carrier
07-02-2011, 00:20
After reading these tales of woe, I will stick with Acurate #9. Almost as fast in the velocity department, but goes bang everytime without problems and meters perfectly everytime.

800-X might be a pain to meter, and have some odd pressure characteristics, but it is undoubtedly the king of the 10mm velocity hill. Also, it will go bang every time. I've never had it fail me. In fact, my carry rounds are loaded with it.

nickE10mm
07-02-2011, 08:40
You are vocalizing a sentiment that I have had for some time now about 800-X.....

....My guess with the huge cushions for pressure found in load data might have something to do with leaving a huge fudge factor for 1) poor metering of 800-X and 2) pehaps the labs are finding some wide variations too. I don't know.

My guess is also the fudge factor they built into the data....

...although it does seem to have an interesting pressure curve. It seems to stop increasing performance for a short while... then a sharp velocity increase (with no real extra pressure signs) at a certain level, around 9.3-9.4gr w/ 200gr XTP, for example.

Do all workups carefully in ONE particular gun and only shoot those loads in that gun... (is my suggestion).

BTW guys, I sent IMR and Hodgdon BOTH an email, since 800X is sold through Hodgdon now, isn't it? (Where did I hear that? weird).... I honestly don't expect a response (don't ask why) but heck, this thread is a great discussion and I would think they would WANT to know whats going on with their powder.

They better not say they don't have the funds for more testing... they are a POWDER MANUFACTURER! What other overhead do they have?? Pressure testing couldn't be THAT expensive for a big company.....

nickE10mm
07-02-2011, 09:11
Also, there are TWO burn rate charts on this page ... interesting data. Note the warning at the top.

http://www.frfrogspad.com/burnrate.htm

headblade
07-02-2011, 20:54
Thanks for the heads up guys. I am in love with 800-X using 180 projectiles and have recently been thinking of trying some 135 gr loads(for showing off at the range) and I had no idea the powder gets weird in them lighter loads. I've loaded about 1500 rounds in 180 grainers and I absolutely love the stuff. I load up to 10.0 gr which is .1 gr less than published maximum for hornady and am seeing 1300 FPS in the G-29 (4.5" KKM) and 1400 FPS (6" KKM) with no pressure signs. Maybe I'll just put the idea of loading for 135 grainers oh HOLD:crying:

TDC20
07-02-2011, 22:29
E-mails sent to both IMR and Hodgdon. If I get any response, I'll report back. If I don't get a response, I may call them (since they tell you to call for safety issues, and I think this could be considered a safety issue).

21Carrier
07-03-2011, 04:11
Well, apparently there's an issue with IMR's email. Here's what I got in return to my email:

This is an automatically generated Delivery Status Notification

THIS IS A WARNING MESSAGE ONLY.

YOU DO NOT NEED TO RESEND YOUR MESSAGE.

Delivery to the following recipient has been delayed:

help@imrpowder.com

Message will be retried for 2 more day(s)

Technical details of temporary failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 421 421 LDAP verification agent temporarily unavailable: Connection failed (state 14).

It sounds like that says that their spam filter service was unavailable so it was rejected. Or maybe the filter just rejected my email. Anyone speak computer?

nickE10mm
07-04-2011, 10:56
Yep, I got the same thing.

We will have to call.

Btw, Hodgdon's email didn't bounce so well wait and see on THEIR email...

Kegs
07-04-2011, 16:19
I will keep loading my 13.3 gr. of 800x behind #300s and 135 noslers.

I like the 1700 fps and 866 fpe.

How much pressure does this load have?

Enough to bust a cap in yo a55.

LOL! - Such a great shooting load.

I don't care if Hodgon came back with the "its dangerous" response. I could have slipped in the shower and died from the statistically more dangerous household environment.

...but seriously, the rest of you guys SHOULD take a break on loading all the noslers since now there is a backorder. :-)

B__
07-17-2011, 15:16
I am too lazy to read everything posted but I will say that the 135 loads are unsafe with mag primers. Wild velocity inconsistencies and pressure signs well below 14.5 grains. Using a plain CCI 300 I can go right up comfortably though I see little gain past 14grns.

TDC20
08-08-2011, 18:08
I finally got a chance to call and got through to Mike at Hodgdon today, to ask him about the 30,000psi numbers that they publish for 10mm Auto. He said since Hodgdon has acquired IMR, they have not re-shot the original testing for the load, and that he would expect the numbers to improve somewhat if they did. He said the main reason for limiting the charges is that there is no more room in the 10mm case unless the charge is compressed. He said that compressed charges with the large flakes of 800-X will break up the flakes, resulting in more surface area exposed which can increast the burn rate. He also said that with this type of flake powder, the flakes are not broken clean, but the edges are left frayed, exposing even more surface area and increasing the burn rate significantly more. So, according to Mike, the safety concern is about the side effects of compressed loads.

So that is the "official" word from Hodgdon on IMR 800-X in the 10mm Auto cartridge. Iím not saying I agree necessarily, but if you have rebuttals, you can take it up with Mike at Hodgdon (913-362-9455).

jeffreybehr
08-08-2011, 19:08
I too used 800-X in my 10mm and my 357SIG...until I did serious research on muzzle flash.
http://jeffreybehr.zenfolio.com/p548446203

Obviously everyone is welcome to do whatever they wish, but if you wish to retain 'night vision' in a personal-defense situation, and lots occur in low light levels, you won't use 800-X.

Kegs
08-09-2011, 08:33
How does a 80+ lumen rail light affect muzzle flash?


I too used 800-X in my 10mm and my 357SIG...until I did serious research on muzzle flash.
http://jeffreybehr.zenfolio.com/p548446203

Obviously everyone is welcome to do whatever they wish, but if you wish to retain 'night vision' in a personal-defense situation, and lots occur in low light levels, you won't use 800-X.

Taterhead
08-09-2011, 10:09
I finally got a chance to call and got through to Mike at Hodgdon today, to ask him about the 30,000psi numbers that they publish for 10mm Auto. He said since Hodgdon has acquired IMR, they have not re-shot the original testing for the load, and that he would expect the numbers to improve somewhat if they did. He said the main reason for limiting the charges is that there is no more room in the 10mm case unless the charge is compressed. He said that compressed charges with the large flakes of 800-X will break up the flakes, resulting in more surface area exposed which can increast the burn rate. He also said that with this type of flake powder, the flakes are not broken clean, but the edges are left frayed, exposing even more surface area and increasing the burn rate significantly more. So, according to Mike, the safety concern is about the side effects of compressed loads.

So that is the "official" word from Hodgdon on IMR 800-X in the 10mm Auto cartridge. Iím not saying I agree necessarily, but if you have rebuttals, you can take it up with Mike at Hodgdon (913-362-9455).

Interesting. That conflicts with a chat that I had with a tech there a couple of years ago (dont remember whom) who said that they had done a re-test after acquiring IMR powders - hence the change in load data. The reason that there was no data for the 135 grainer was that they had not re-tested it. I asked if there was a plan for testing the 135 and he said no due to insufficient interest in the cartridge in general. Who knows what the real deal is.

GTRhino24
08-09-2011, 13:45
I too used 800-X in my 10mm and my 357SIG...until I did serious research on muzzle flash.
http://jeffreybehr.zenfolio.com/p548446203

Obviously everyone is welcome to do whatever they wish, but if you wish to retain 'night vision' in a personal-defense situation, and lots occur in low light levels, you won't use 800-X.

I use Blue Dot to blind and burn the intruder and then echolocation to finish him off. Meanwhile, my basset hound is trained to gnaw at their ankles.

robert91922
08-09-2011, 14:31
How does a 80+ lumen rail light affect muzzle flash?
When your 80+ lumen rail light is switched on your eye pupil is less opened than in darkness, so muzzle flash doesn't effect your natural night vision so much.
Anyway this muzzle flash problem could be a serious issue for SD shooting in dark or at dim light.
This thread gave me idea to test my woods carry load in darkness as well, because many hunting trips begin in morning dim light or end in evening darkness.

21Carrier
08-09-2011, 15:07
TDC, that really worries me to hear 800-X might get sketchy when compressed. I'm sitting on some VERY compressed 800-X loads (125gr Barnes bullets) that I'll test as soon as my locking block comes in (Thursday). It makes sense that it would increase the surface area, IF they really break up, but they don't seem like they would get broken up too easily. I guess we will see Thursday if compression causes problems.

hypnagogue
08-09-2011, 15:50
That makes no sense; look at the data.hodgdon.com 800X load for 200 XTP in 40S&W -- 6.1 grains at 1.125 COAL. That's a compressed load equivalent to ~9.0 grains in 10mm with the same projectile.

I call bunk.

Taterhead
08-09-2011, 16:50
TDC, that really worries me to hear 800-X might get sketchy when compressed. I'm sitting on some VERY compressed 800-X loads (125gr Barnes bullets) that I'll test as soon as my locking block comes in (Thursday). It makes sense that it would increase the surface area, IF they really break up, but they don't seem like they would get broken up too easily. I guess we will see Thursday if compression causes problems.

One way to find out is to pull a bullet and look for crumbs. This compression thing sounds a bit weird to me. 800-X is squishy with a bit of air space. That is why 14.5 grains will fill a case completely (I do not recommend this). Tapping on the side of the case settles the powder a bit so that you can start a 135 gr bullet. Compressing feels more spongy to me. I don't get the sensation that I am crushing the powder into smaller pieces. I could be wrong. I am certainly no ballistician.

21Carrier
08-09-2011, 17:21
One way to find out is to pull a bullet and look for crumbs. This compression thing sounds a bit weird to me. 800-X is squishy with a bit of air space. That is why 14.5 grains will fill a case completely (I do not recommend this). Tapping on the side of the case settles the powder a bit so that you can start a 135 gr bullet. Compressing feels more spongy to me. I don't get the sensation that I am crushing the powder into smaller pieces. I could be wrong. I am certainly no ballistician.

I agree. With 800-X having such large flakes, there's a lot of airspace. Even though my loads are pretty compressed, I doubt they are compressed enough to damage the flakes. None of the bullets sprung back out, either, so I took that as a good sign.

hypnagogue
08-09-2011, 20:13
.. look at the data.hodgdon.com 800X load for 200 XTP in 40S&W -- 6.1 grains at 1.125 COAL. That's a compressed load equivalent to ~9.0 grains in 10mm with the same projectile.

I just redid my math, with measurements instead of estimates. The 40 S&W load in their database is actually compressed 150%, which is equivalent to ~10.0 grains in the 10mm case. Thus, if you stay under 10.0 grains, you will be compressing your charge less than Hodgdon's own 40 S&W maximum.

nickE10mm
08-10-2011, 07:40
I just redid my math, with measurements instead of estimates. The 40 S&W load in their database is actually compressed 150%, which is equivalent to ~10.0 grains in the 10mm case. Thus, if you stay under 10.0 grains, you will be compressing your charge less than Hodgdon's own 40 S&W maximum.

Quite interesting....

TDC20
08-10-2011, 12:06
TDC, that really worries me to hear 800-X might get sketchy when compressed. I'm sitting on some VERY compressed 800-X loads (125gr Barnes bullets) that I'll test as soon as my locking block comes in (Thursday). It makes sense that it would increase the surface area, IF they really break up, but they don't seem like they would get broken up too easily. I guess we will see Thursday if compression causes problems.

This conversation with Hodgdon isn't going to change my 800-X loads at all. I haven't heard of anyone blowing up a gun except with the old IMR published max 135gr loads. For 180 and 200 gr bullets, my pressure signs are moderate and consistent, and I have extremely low standard deviations on my velocities. More so than other powders for the same bullets. All telling me that these loads are safe and consistent.

I really wanted to argue with the ballistician, but what was I going to say? You're wrong? I did tell him that there was a large following of people loading 800-X for the 10mm Auto, that it had top performance compared to other powders, and that if Hodgdon updated their load data it would really be helpful, since people are already loading beyond their recommendations with excellent results. He had a cautionary safety response, which I suppose he was obligated to do.

I agree with everyone here, there is a lot of air space due to flaky nature of 800-X. But, the flakes are springy and personally I don't think you can compress them enough within the boundaries of a safe charge to cause significant damage to the integrity of the flakes. It's not like I'm mashing them in with a wooden dowel and hammer, or getting bullet springback or case bulges after seating these loads. I'm usually very conservative concerning load data and powder recommendations, but in this case, I firmly believe that this was a standard "safety first" response, and that the 10mm reloading community is not seen as providing enough 800-X sales for Hodgdon to justify the necessary ballistics testing to establish true safe load boundaries at or near the 37,500psi mark.

That's my opinon, YMMV. I don't see where 800-X provides any significant pressure/performance improvement over Longshot for bullets under 180gr., so personally, I feel there are better powders for that, even if the only advantage is metering properties. I'll continue to use 800-X for full power 180 and 200gr. loads

nickE10mm
08-10-2011, 12:10
.... and that the 10mm reloading community is not seen as providing enough 800-X sales for Hodgdon to justify the necessary ballistics testing to establish true safe load boundaries at or near the 37,500psi mark.


I think its ridiculous that they can't re-test their info. I mean, what exactly do they DO there at Hodgdon all day long? Isn't powder and ballistics testing their JOB?

Hmm

21Carrier
08-10-2011, 21:59
TDC, do you have some data for Longshot with 135gr bullets? Does it do as well as 800-X?

TDC20
08-11-2011, 00:27
TDC, do you have some data for Longshot with 135gr bullets? Does it do as well as 800-X?

Here's my "urban carry" load:

135gr. Nosler HP, 12.6gr Longshot, CCI #300, New Starline Brass, 1.255" OAL, 62F

G20, 6" LWD barrel, 22lb spring

1750
1726
1707
1721
1686

Lo 1686
HI 1750
Avg 1718 (885.0 ft-lbs)
Es 64
Sd 23.67

Notes: Case heads .4228 - .4232" (unfired was .422"). Light to moderate ejector/extractor marks.


Same load fired from Stock G20 4.6" barrel with Wolff 22lb recoil spring:

1593
1596
1604
1558
1547

Lo 1547
HI 1604
Avg 1579.6 (748.1 ft-lbs)
Es 57
Sd 25.36

Notes: Case heads .4232 - .4237". Moderate ejector/extractor marks.

This isn't a super accurate load, but it will group about 4-5" at 25 yards. Some of that could be me, because it does have a bit of a snappy recoil. It's pretty easy on the brass even from the Glock barrel, and about 50fps faster than what I was getting from the 6" barrel with 12.5gr of 800-X and a CCI #300 primer.

XmmAUTO
08-11-2011, 22:58
Manufactures are not showing the higher loading data of years past for several reasons but mostly liability reasons. They have no idea what a handloader will be putting into what casing, with what primer and shot thru a gun with no knowledge of its condition. So they revised the data to reflect a larger safety margine taking the unknowns into account. The statements like use "current data" play into their hands for this reason.

This is exactly what manufacturers are doing. Publishing max pressure data will give some the idea that a load is ok to shoot in any gun. However we know this is not the case.

Here is yet another thought to ponder...FMJ, FMC, JHP, Lead Free

Each of these bullets may weigh the same but be very different in total length and space occupied within the cartridge case. This can and does affect pressure based on the powder compression or free space... same amount of powder but less space increases pressure.

Pressure test barrels (fixed and round so the strain can be wrapped) that they use a strain gauge wrapped are usually compared to know test performed. I suppose it is based on the expansion of the barrel metal acting on the strain gauge...repeatable and instant read out as a graph over time via computer.

I think he old C.U.P. method was probably more precise based on the crushed copper disk of known compressive forces. This was slow and could only be use once per disk which had to be evaluated as a maximum.


Every bullet gives different results. Even a 180 FMJ from Speer will give different results than a 180 FMJ from Hornady.

Strain gauges measure the expansion of the steel. The brass case must be measured as it is also accounted for in the formula used to calculate the modulus of elasticity of the barrel steel to a output in PSI. As far a C.U.P
being precise, it may be but are the results repeatable with great accuracy. The copper used can vary in its consistency which will affect results. The strain gauge is a more repeatable system and can be re-calibrated after every shot.

However, since Hodgdon's data shows the max load for 180gr bullets at 30,000 psi, there's clearly more margin there than what is published. I've cautiously loaded beyond the published level, but that always bothers me.
This is where the manufactures are doing it all wrong IMHO.
This is why I have invested almost $2000 in equipment to create the most comprehensive collection of 10mm load data EVER!



Gee, how about some up to date and relevant data guys? Especially with the bullets we're using?

What if all of us dedicated 10mm re loader's and 800-x fans, start an email campaign asking them to provide us with some more 10mm data, even going as far as telling them what loads we're developing and asking if they'd kindly provide feedback and support of their product?

Couldn't hurt and we might learn something?

As 21 said, without cost prohibitive equipment, we're flying by the seat of our pants here.
The Data will be here in time. Don't waste your time e-mailing the big manufacturers. They don't believe that the 10mm is profitable. I do. The profit is in the reloading market.

What we may see happen in the future, is that the pressure numbers maybe absent from the data. MHO is that this would leave the handloader blind to where the loads are in any shown data...Sad if they do.
The pressure numbers will likely go away. But do you believe in a resurrection.


Obviously, if y'all have ever seen anything I do (the wax tests for instance), you know I love data, so I would RATHER have all the data possible. Hell, it would be ideal if they would provide pressure charts or graphs that would give pressure vs. time, and area under the curve. With that, we could REALLY do some learning. But I'll be satisfied if they just update the data to true maximums.


21Carrier, dreams do come true. Most if not all of you know what I'm working on doing. I know that there are skeptics among us but I will let my data speak for itself.

To give you an idea of what you will see:

10mm Auto
Bullet
Bullet Manufacturer
Case Manufacturer
OAL 1.26"
CCI #300 Primer
Primer Lot#
Powder
Powder Lot#
In HG
Humidity
Temperature
Test barrel Length

Powder Charge #1 (10 shot string)
% Capacity (ie. how much does the powder charge fill the case)
Pressure(Ave,SD,ES,Low,High,95% Probability,Area under the curve,Rise,Efficiency)
Velocity(Ave,SD,ES,Low,High,95% Probability)
Energy(Ave,SD,ES,Low,High,95% Probability)
External ballistics chart for bullet drop data


Including the graphs themselves. After all charge weights have been shot you will see graphs with Powder charge weight vs. Velocity, Powder charge weight vs. Pressure, Pressure vs. Velocity

Not to mention group size and future ballistics gel testing

Will this be enough data for you?

_The_Shadow
08-12-2011, 10:40
XmmAuto, writes; Every bullet gives different results. Even a 180 FMJ from Speer will give different results than a 180 FMJ from Hornady.

Strain gauges measure the expansion of the steel. The brass case must be measured as it is also accounted for in the formula used to calculate the modulus of elasticity of the barrel steel to a output in PSI. As far a C.U.P
being precise, it may be but are the results repeatable with great accuracy. The copper used can vary in its consistency which will affect results. The strain gauge is a more repeatable system and can be re-calibrated after every shot.


Please don't take me wrong here, because I am one who can appreciate the investment, the hard work and the dedication to which you are set to acommplish and even share the results of your data to satisy the unknowns we all seek!

While the fired cartridge is acitng upon the barrel from the inside out, it just seems that the strain gauge is more of a measurement of the barrel's flexation/expansion. I suppose this is why the data is useable and repeatable.
Then there are some things like the the cartridge needing to expand to the point of filling the chamber, before it acts upon the chamber.
Bullet jump to engage the rifling to actually seal the bore to contain the building pressures. This maybe the most widely cause of fluctation in the pressure building. With semiauto uses we have seen the COAL shifted to allow better reliabilities.

I believe these two can have the greatest affect on the peak pressure spike and mean the difference in what works for some and not others.

Also the Glock barrels chamber spec., free bore(amount of space the bullet needs to jump) , rifling and fast twist rate is so different than that other barrels with tighter chamber specs. and conventional rifling with slower twist rates.

Therefore the data you compile will be useful but specific to the test barrel and the specifics of the load of the test. These results will vary as tested in other barrels but will provide some guidelines for those who understand the processes and can utilize the data you share.

Someday there will be even better systems for providing the pressure data...Who knows it may even be you who comes up with a better sensor/strain gauge to yeild even more accurate results!:wow:

Best regards!:wavey:

hypnagogue
08-12-2011, 20:00
XmmAuto, writes;
Therefore the data you compile will be useful but specific to the test barrel and the specifics of the load of the test. These results will vary as tested in other barrels but will provide some guidelines for those who understand the processes and can utilize the data you share.

I've never seen the variation between barrels with respect to peak pressure that you describe. I have seen variations in velocity, and variations in case deformation. But to claim that peak pressures in a fully supported to-spec chamber are not applicable to other barrels? No, I don't think so. If anything, the TC barrel is a more disciplined approach to testing, representing worst-case pressures, and the pressures in unsupported barrels will be lower.

If a given load is below SAAMI maximum average pressure in a fully supported, to-spec chamber, then it is a to-spec load. If that same load develops less pressure and less velocity in a non-spec chamber, that's not relevant.

21Carrier
08-12-2011, 22:35
Here's my "urban carry" load:

135gr. Nosler HP, 12.6gr Longshot, CCI #300, New Starline Brass, 1.255" OAL, 62F

G20, 6" LWD barrel, 22lb spring

1750
1726
1707
1721
1686

Lo 1686
HI 1750
Avg 1718 (885.0 ft-lbs)
Es 64
Sd 23.67

Notes: Case heads .4228 - .4232" (unfired was .422"). Light to moderate ejector/extractor marks.


Same load fired from Stock G20 4.6" barrel with Wolff 22lb recoil spring:

1593
1596
1604
1558
1547

Lo 1547
HI 1604
Avg 1579.6 (748.1 ft-lbs)
Es 57
Sd 25.36

Notes: Case heads .4232 - .4237". Moderate ejector/extractor marks.

This isn't a super accurate load, but it will group about 4-5" at 25 yards. Some of that could be me, because it does have a bit of a snappy recoil. It's pretty easy on the brass even from the Glock barrel, and about 50fps faster than what I was getting from the 6" barrel with 12.5gr of 800-X and a CCI #300 primer.

I'm pretty sure this is the second time I've seen these measurements from you (not these exact ones, but same range). Are you SURE you don't mean .4332-.4337"? If your measurements are indeed correct, my G29 barrel is WAY oversized. I get expansion around .433-.435". My max is .435". Are the stock G20 barrels really that much tighter?

On another note, I just got my 135gr Nosler JHPs in today, so I'll have to try some Longshot loads. I just loaded up 50 with 13.0gr 800-X (CCI 300s, COAL 1.260"). If pressure allows it, you should try that load. I am 99.9% sure it would be fine in either barrel, but ESPECIALLY in the LWD barrel. I've never had pressure signs in my G29 barrel, and I average 1560fps out of my G29. Thanks for the Longshot load. I'm going to start a work-up around 11.6gr, and work up from there.

XmmAuto, I absolutely can't wait for you to start gathering data. I can't wait to see some pressure graphs from 800-X. Hell, I'd be happy to look at 10mm pressure graphs from UNIQUE!!! I really appreciate what you're doing. If I had the money to spare, I would have bought the stuff too. It will be fun to see the data you post, but it would be even more fun to actually do the testing.

TDC20
08-13-2011, 12:19
I'm pretty sure this is the second time I've seen these measurements from you (not these exact ones, but same range). Are you SURE you don't mean .4332-.4337"? If your measurements are indeed correct, my G29 barrel is WAY oversized. I get expansion around .433-.435". My max is .435". Are the stock G20 barrels really that much tighter?

No Carrier, you are exactly right, if you measure the brass at the maximum expansion point. My brass fired from my G20 barrel measures right around .433-.434 at the maximum expansion point. What I measure instead is the case web dia. just below that max expansion point and above where the extractor groove starts. My reasoning is that the max. expansion point is relative to the barrel's chamber dimensions, and is really measuring the amount of brass springback after pressure drops. The max expansion point measurement will also tell you something about where your pressure peaks, but in that particular barrel only, and to me the changes measured there between different pressure levels seemed like they were more difficult to differentiate, making them statistically harder to compare than measurements made at the web. My opinion is that, for me anyway, max. case expansion isn't as valuable for comparative purposes as the web expansion, so that's why I measure at the web instead. This was the method as explained in a Rifle magazine article that I read probably 10 years ago. I'm not sure if the author of this article was Ken Waters or not, but I can tell you with certainty from many measurements of many cases with different loadings that it IS an accurate data point that is proportional to the pressure of a given load.

On another note, I just got my 135gr Nosler JHPs in today, so I'll have to try some Longshot loads....I'm going to start a work-up around 11.6gr, and work up from there.

That should be a good starting point. I worked up to my load using Mike McNett's posted Longshot data as my "backstop":

"Starline Brass, CCI 350 primers, 1.26" OAL. 10 shot avg. G20 85F and 5000ft elevation.
135gr Nosler 13.2gr LS - 1542fps
"These are loads that I have worked up to and are under 37,500psi when I had them tested."

Except that I used CCI #300 primers, and got past his velocity data with 0.6gr less powder. I'm not really sure why the discrepancy except for OAL, but I don't think there's any way .005" could make that big of a difference. I would back down quite a bit lower than 11.6gr if you were starting with CCI #350's for this reason, but with #300's, you should be plenty safe starting at 11.6. I started at 12.3 with the CCI#300's thinking I would have plenty of margin, and got 1680fps right off (6" barrel), so I didn't have very far to go. It's quite possible that Mike made a typo and meant 12.2 or 12.3. All I know is that in my G20 stock barrel with a 22lb spring, I haven't gotten even hints of Glocksmiles with my CCI#300 and 12.6gr. load. So for me they are safe.

_The_Shadow
08-13-2011, 13:16
I've never seen the variation between barrels with respect to peak pressure that you describe. I have seen variations in velocity, and variations in case deformation. But to claim that peak pressures in a fully supported to-spec chamber are not applicable to other barrels? No, I don't think so.

Are you stating that you have run pressure testing with the strain gauge or other methods to show pressure curves? What cartridges did you work with? I understand the measuring of the expanded cases as a reference to pressure vs. chamber and brass used.

If anything, the TC barrel is a more disciplined approach to testing, representing worst-case pressures, and the pressures in unsupported barrels will be lower.

If a given load is below SAAMI maximum average pressure in a fully supported, to-spec chamber, then it is a to-spec load. If that same load develops less pressure and less velocity in a non-spec chamber, that's not relevant.

I'm not debating that the loads in the T/C barrel tested to be inside a pressure specification MAP, and I am looking forward to XmmAuto's testing and data.

I suppose what I am trying to say is that there will be small changes in the pressure curve for one gun/barrel to the next for a specific loading. These changes can have affects to timing of the slide and feeding which may work right in one pistol, but cause it not run reliably in another. Can some of the loads which fit the MAP seen in the T/C barrel test actually exibit higher pressures? I think yes if conditions present themselves. One example would be a bore which has leading. What people need to understand here is; Different lot #'s of powders also come to mind, even though very close, primer sustitutions, thickness of brass casings from different makers and bullet sustitutions can show differences if they are coping and using the data, especially at the extreme upper end of performance.

I have seen loads using slower burning powders cause cases to stick in the chambers of semiauto's becuse the pressure did not drop low enough at the time of the ejection cycle, cases get left in the chamber, extraction rims can get ripped off or damage to the extractor can occur.

Although I have been loading for may years and various cartridges I am here to learn as much as share!:wavey:

hypnagogue
08-13-2011, 13:59
I started at 12.3 with the CCI#300's thinking I would have plenty of margin, and got 1680fps right off (6" barrel), so I didn't have very far to go. It's quite possible that Mike made a typo and meant 12.2 or 12.3.

It's not a typo. You are testing with a longer barrel, so you are seeing higher velocities.

TDC20
08-13-2011, 14:40
It's not a typo. You are testing with a longer barrel, so you are seeing higher velocities.

Yeah hypnagogue, I was referring to my previoulsy posted data, where I am getting 1580fps from a stock G20 4.6" barrel using CCI#300's and 12.6gr., vs. McNett's 1542fps using CCI#350's and 13.2gr. out of presumably the same gun. That's the "discrepancy" I was referring to.

hypnagogue
08-13-2011, 15:59
Yeah hypnagogue, I was referring to my previoulsy posted data, where I am getting 1580fps from a stock G20 4.6" barrel using CCI#300's and 12.6gr., vs. McNett's 1542fps using CCI#350's and 13.2gr. out of presumably the same gun. That's the "discrepancy" I was referring to.

It's not a discrepancy. That velocity difference is in line with my measured SD on that load. Also, with light bullets and slow powders you will see very little difference with only 0.6 grains of powder, particularly when the velocity is limited by barrel length. In my testing, velocity topped out at 12.5 grains as well. Going to 13.2 will not increase velocity in a 4.6" barrel (at least, I never saw it), but will increase velocity in a 6 inch barrel.

McNett was stating that he tested 13.2 and 350s and that it was under 37.5k. He didn't state that it was faster than 12.6 in a 4.6 inch barrel. My experience with CCI 300 and CCI 350 in that load is that the 350s increase peak pressure, but don't increase velocity. I think the 300s work better. Given the variables at work here, I don't see any surprises.