Inconsistent OAL Variance for 9mm [Archive] - Glock Talk

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GhettoSmack
11-18-2011, 09:13
Here are the details:
Dillon XL650 w/UniqueTek Toolhead Clamp Kit
Station 1: Dillon Sizer/Deprimer die
Station 2: Dillon powder die and powder dispenser
Station 3: Empty
Station 4: Redding Competition Micrometer seater die
Station 5: Lee Carbide Factory Crimp/Full-length Sizer die

I've been loading .45ACP on this press with the same die setup for almost a year with excellent results (OAL variance of +- .002"). Berry's 230gr Plated RN @ 1.260". (Montana Gold 230gr CMJ varied +- .005 due to ogive.)

I started loading 9mm and OAL variance is +- .005. 124gr Berry's Plated RN. I've loaded ~500rnds.

My dies are clean. Everything is tight. The rotating case retention plate is tight without binding. I'm using mixed already-fired range brass.

So what's the deal?? Are my cases not clean enough? Is it case length difference? Is it just the bullet shape matched to the seating die shape?

Thanks for your comments and experience.

Colorado4Wheel
11-18-2011, 09:16
So are you saying you have it set for (for example) to 1.130 and it varies from 1.125 to 1.135

Or

You have it set to 1.130 and it varies from 1.128 to 1.133?

fredj338
11-18-2011, 09:26
So are you saying you have it set for (for example) to 1.130 and it varies from 1.125 to 1.135

Or

You have it set to 1.130 and it varies from 1.128 to 1.133?
Even the worst case, a variation of 0.005" isn't hurting anything. You probably have a bad batch of Berry's bullets w/ more deviation in the nose shape than should be.
Steve brings up a good point below. Mixed brass. Thre is a lot of variation in 9mm brass & that always affects OAL, especially w/ soft plated or lead bullets.

Colorado4Wheel
11-18-2011, 09:29
Even some nicks on the base/rim of the brass will lead to more OAL variation. +/-.005" ain't a big deal. Just to make you feel worse, I get better then that with a stock toolhead, mixed brass and a Lee seating die.
Might want to make sure you tighten the lock ring with the bullet/case combo in the die.

mogollon
11-18-2011, 09:29
Most likely it is simply ogive variation from one bullet to the next. You can verify this by removing the seating stem from the seating die, place it over the nose of the bullet, and measure from the base of the bullet to the top of the seating stem. (mm is more prone to this than 45, simply due to the smaller diameter.

rpgman
11-18-2011, 09:51
yep, I sort my brass, both 9mm and .40.

F106 Fan
11-18-2011, 10:12
Is it just the bullet shape matched to the seating die shape?


This can certainly be a problem. I am using both the Redding Competition and the Dillon seating dies and I have some variation as well. I am pretty convinced that the shape of the nose of the bullet isn't consistent.

It might be interesting to see if the variation is different when you load Sierra Match bullets versus bulk jacketed or plated bullets. I wonder if I am getting anything for that 'match' designation. And, no, I am not loading match bullets at the moment.

Richard

GhettoSmack
11-18-2011, 10:20
Clarification:
I'm TRYING loading 9mm to 1.150. The loaded and crimped rounds come out from 1.145" to 1.155" . Variance of +- 0.005; total variance of 0.010.

These are for competition (IDPA, USPSA). I am a little OCD so I like CONSISTENCY. My concern is that chrono-ing a round 1.155" will not meet [Minor] PF and 1.145" - 1.150" will be on the line. Practice rounds are one thing, but competition rounds I want THE SAME with no surprises. (Do I sound like a bullseye shooter? haha)

GhettoSmack
11-18-2011, 10:22
Thanks for your comments and suggestions. Sounds like bullet shape and case length might be the biggest culprits. I may have to experiment with different manufacturers to see which ones fit the seater die the best = most consistent. I just don't want to spend too much on FMJ compared to Plated.

Then, again .... what's the harm in loading practice rounds (low cost, inconsistent length plated) and competition rounds (higher cost, consistent FMJ)? Nothing wrong there!

F106 Fan
11-18-2011, 10:40
I would assume you are loading to 130 PF instead of trying to cut it really close. After all, the tests aren't going to be done with your barrel and there is no 'standardized' chronometer. You need some slack.

So, load some short - say 1.140" and some long at 1.160" and see what difference it makes.

My guess is that the difference will be much smaller than the difference between 40 deg F and 110 deg F. Heck, you may find that keeping the cartridges in your pocket results in 10 fps over letting them sit around in cold air. Always turn in the warm shells.

Look at the standard deviation of your strings. Try to get a load that has minimal deviation. I have a load with Berry's 147 gr and 3.5 gr Bullseye with a standard deviation of 3.5 fps. The average is 906 fps and extreme spread is only 12.2 fps. The PF is 133.

I used to race small hydroplanes with a 400# class minimum weight (boat plus driver and remaining fuel) which was measured AFTER the race. The trick was to jump out of the boat as you beached it to 'help' keep it from crashing into 'something'. And wear wool jogging clothes because you can pick up 10# of water before you get back in the boat.

Everybody wants to push the limits!

Richard

ron59
11-18-2011, 11:59
I know with my 147gr Montana Gold CMJ, my OAL was +/- .002"

With the Bear Creek Molys (also 147gr) that I'm using now, it's more like +/- .005" (if not .007"). Fred mentions that soft plated or lead bullets can/will affect OAL, certainly seems true for me too.

rpgman
11-18-2011, 12:18
even though I sort my brass for both 9mm and .40, I still get a +/- .005 on some.

fredj338
11-18-2011, 13:27
Clarification:
I'm TRYING loading 9mm to 1.150. The loaded and crimped rounds come out from 1.145" to 1.155" . Variance of +- 0.005; total variance of 0.010.

These are for competition (IDPA, USPSA). I am a little OCD so I like CONSISTENCY. My concern is that chrono-ing a round 1.155" will not meet [Minor] PF and 1.145" - 1.150" will be on the line. Practice rounds are one thing, but competition rounds I want THE SAME with no surprises. (Do I sound like a bullseye shooter? haha)

If your loads are that close, then stop gaming & add a safety factor in. I doubt 10PF is going to make or break you in a match. a 0.010" OAL variation isn't going to change vel more than std deviation anyway.:dunno:

GhettoSmack
11-18-2011, 14:11
fredj338 - I guess you're right. 0.010 variance shouldn't affect PF that much. It's just frustrating to have to measure all finished rounds and separate.

0.010 variance OAL works fine in my "plastic fantastic" guns and CZ85. My 9mm 1911 is much more picky. It loves S&B @ 1.155" AOL, but doesn't care much for -common reloading retailer- at 1.150. So I load for my 1911 and it works in all my others.

From the current posts, it appears I am not the only one with the variance issue.

rpgman
11-18-2011, 14:26
fredj338 - I guess you're right. 0.010 variance shouldn't affect PF that much. It's just frustrating to have to measure all finished rounds and separate.

0.010 variance OAL works fine in my "plastic fantastic" guns and CZ85. My 9mm 1911 is much more picky. It loves S&B @ 1.155" AOL, but doesn't care much for -common reloading retailer- at 1.150. So I load for my 1911 and it works in all my others.

From the current posts, it appears I am not the only one with the variance issue.

I'm sure we all have a variance issue. I measure only every 5th case.
If it's within the +/- .005 of my OAL of 1.130 for my 9mm and .40 I'm fine with that.

ron59
11-18-2011, 14:35
Clarification:
I'm TRYING loading 9mm to 1.150. The loaded and crimped rounds come out from 1.145" to 1.155" . Variance of +- 0.005; total variance of 0.010.

These are for competition (IDPA, USPSA). I am a little OCD so I like CONSISTENCY. My concern is that chrono-ing a round 1.155" will not meet [Minor] PF and 1.145" - 1.150" will be on the line. Practice rounds are one thing, but competition rounds I want THE SAME with no surprises. (Do I sound like a bullseye shooter? haha)

Instead of having a concern, you should actually TEST this situation.

You have a chrony, don't you? shoot 15 of them. 5 that are 1.155" and 5 each at the short/long versions. I bet you don't get more than about 15-20fps difference out of them, which isn't much. I target my load at 133PF or so with my 9mm, I want a comfortable cushion.

GhettoSmack
11-18-2011, 22:47
Actually, I do not have a chronograph. No one I know -- many reloading competition shooters -- has one, either. At least not one they will let me use. I wish I COULD test the loads at different lengths. That's why I asked YOU GUYS ... the ones with a chrono and experience.

From what I gather, if 0.010" OAL variance equals ~10PF, then loading rounds to 130PF at the short length (1.145") will be at ~120PF at the long length (1.155"). That's a DQ in competition (min 125PF). To cover that variance, I would need to load to 135PF.

I'm not saying that is good or bad.

So I will experiment with different bullet manufacturers to see which shape is more consistent in my press (seater die). Although .... I might try TWO seater dies (have an empty stage in my XL650). The first die to seat the bullet about 0.010 longer than desired. Then the 2nd seater die as the "finish" length. Anyone ever try this?

Boxerglocker
11-18-2011, 23:39
Actually, I do not have a chronograph. No one I know -- many reloading competition shooters -- has one, either. At least not one they will let me use. I wish I COULD test the loads at different lengths. That's why I asked YOU GUYS ... the ones with a chrono and experience.

From what I gather, if 0.010" OAL variance equals ~10PF, then loading rounds to 130PF at the short length (1.145") will be at ~120PF at the long length (1.155"). That's a DQ in competition (min 125PF). To cover that variance, I would need to load to 135PF.

I'm not saying that is good or bad.

So I will experiment with different bullet manufacturers to see which shape is more consistent in my press (seater die). Although .... I might try TWO seater dies (have an empty stage in my XL650). The first die to seat the bullet about 0.010 longer than desired. Then the 2nd seater die as the "finish" length. Anyone ever try this?

You are worrying over nothing.... 0.005 +/- with you set up isn't gonna have any drastic variance in PF. I have almost the exact same set-up (plus shell plate bearing kit) use 135g Bear Creek molys, mixed brass with WST 1.150 inch OAL target. Usually at 0.005 +/- my loads have officially chronoed at state matches consistently. Last State IDPA 1024, 1024 and 1019 fps. (It was noted by all the official chrono was generous by about 20 fps. on my chrono consistent at 1000 fps, my target PF is 135.)

BuckyP
11-19-2011, 03:52
I would assume you are loading to 130 PF instead of trying to cut it really close. After all, the tests aren't going to be done with your barrel and there is no 'standardized' chronometer. You need some slack.


In USPSA they chrono through your gun / barrel.


You are worrying over nothing.... 0.005 +/- with you set up isn't gonna have any drastic variance in PF. I have almost the exact same set-up (plus shell plate bearing kit) use 135g Bear Creek molys, mixed brass with WST 1.150 inch OAL target. Usually at 0.005 +/- my loads have officially chronoed at state matches consistently. Last State IDPA 1024, 1024 and 1019 fps. (It was noted by all the official chrono was generous by about 20 fps. on my chrono consistent at 1000 fps, my target PF is 135.)

This. I also agree going a little over 130, my goal PF is 132-133. That should give you a bit a leeway, and you won't even notice an extra 2 to 3 PF

Colorado4Wheel
11-19-2011, 04:43
From what I gather, if 0.010" OAL variance equals ~10PF, then loading rounds to 130PF at the short length (1.145") will be at ~120PF at the long length (1.155"). That's a DQ in competition (min 125PF). To cover that variance, I would need to load to 135PF.

I'm not saying that is good or bad.

No wonder you are so freaked out. That is wrong in a huge way. No way a .01 change makes a 10pf difference at that oal. Maybe a 1-2 pf difference. IDPA'ers like to take their game a little too seriously sometimes. Stop worrying about it. Have fun. Don't waste your money on anothet seating die.

ron59
11-19-2011, 07:58
No wonder you are so freaked out. That is wrong in a huge way. No way a .01 change makes a 10pf difference at that oal. Maybe a 1-2 pf difference. IDPA'ers like to take their game a little too seriously sometimes. Stop worrying about it. Have fun. Don't waste your money on anothet seating die.

I've never done a test to verify that, but is exactly what I was thinking as well. 10PF is a LOT of difference (130 to 120). I don't see that little OAL difference being anywhere near that. My gun probably wouldn't cycle reliably with 120PF 147gr stuff.

fredj338
11-19-2011, 08:18
Actually, I do not have a chronograph. No one I know -- many reloading competition shooters -- has one, either. At least not one they will let me use. I wish I COULD test the loads at different lengths. That's why I asked YOU GUYS ... the ones with a chrono and experience.

From what I gather, if 0.010" OAL variance equals ~10PF, then loading rounds to 130PF at the short length (1.145") will be at ~120PF at the long length (1.155"). That's a DQ in competition (min 125PF). To cover that variance, I would need to load to 135PF.

I'm not saying that is good or bad.

So I will experiment with different bullet manufacturers to see which shape is more consistent in my press (seater die). Although .... I might try TWO seater dies (have an empty stage in my XL650). The first die to seat the bullet about 0.010 longer than desired. Then the 2nd seater die as the "finish" length. Anyone ever try this?
There is no linear correlation between OAL & vel, it's powder, bullet & cartirdge specifc. The only way to know is chronograph. No truely serious competitions shooter wings it. If you want to know, buy a cheap Chrony (can't believe I said that), but shot to shot variation can be as much 30fps w/ the same load. Right now, you have only a WAG what the load is running.:dunno: Really, I wouldn't worry about.

GhettoSmack
11-19-2011, 15:08
OK. OK. I'll TRY to quit obsessing over the OAL variance since it won't/shouldn't affect PF that much. (I'll look for medication for my OCD. haha)

It makes sense that consistent powder charge is the more important component in PF.

I will move on to ensuring the cartridges feed reliably in the barrels of the guns I shoot.

engineermike
11-19-2011, 15:52
I've had the same problem for a while using round nosed bullets and Hollow point bullet while using the round nose seater pin/plug. It can be that the seater plug is not the right size for the bullet, and it could be the bullet not setting straight in the case mouth and the ogive is not hitting the center of the seater plug. I have been told that using the Lyman M die seater may help with the bullets not setting straight on the case mouth but have not purchased a lyman die yet to test this. I've has some luck using the flat seater pin/plug but on round nosed bullets that might not be a great idea as the ogive on the bullet is going to be more consistent spot on the bullet more so than the bullet nose. (Something to do with bullets coming out of molds) I use Hornady dies and find that lightly setting the bullets on the case mouth, instead of pushing them into the case mouth, works a little better but I still find a few where the over all length is off more that .003. I too am still hitting my head against the wall over this, I guess I need meds. :faint:

Colorado4Wheel
11-19-2011, 16:15
The Redding Seating die should solve all the issues with Jacketed bullets. It has a spring loaded sleeve that pre-aligns the bullet straight to the case before it's inserted. Once that happens the shape of the bullet should not matter (assuming every bullets ogive is the same, which it never is). Even a small variance in ogive is not going to result in a .010 OAL change. Something else is creating that change. Also, the Lyman M-Die is not that different then his existing Dillon powder through expander. I actually prefer the Dillon Setup.

I got to wonder if GhettoSmack is check some bullets OAL with a full shellplate and others created with a empty shellplate. His Dillon Seater sucked, his Redding is not that great. He has every mod to the press possible. It just doesn't add up. Maybe he has mixed brass, maybe not enough flare. But .010" total difference is WAY more then I ever get on my 650 with my cheap old Lee dies. Not that the .010" makes much of a difference. It's just that he seems to not have good results with anything he tried so it makes me think something else is contributing to the issue as well.

GhettoSmack
11-21-2011, 12:02
I agree with you, Colorado4Wheel.

I just found something on Redding's site ... they actually address OAL variations on their Tech Line and Tips page!
http://www.redding-reloading.com/tech-line-a-tips

Here is the synopsis for causes of OAL variance:
- Inconsistent bullet ogive. (Likely.)
- Warn reloading press ram. (Possible, but unlikely.)
- Inadequate or excessive neck tension. (Will consider.)
- Heavily compressed loads. (N/A)

When in doubt .... ask the guys that made this stuff.