well, now I know what a glock smile is :( [Archive] - Glock Talk

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JimIsland
12-11-2011, 12:11
Went the range yesterday and tried some DT ammo (165 grain hollow points) The box said 1400 FPS but I'm not sure how accurate that is. Anyway, I put about 10 rounds through my stock Gen2 G20 and after retrieving my casings, found smiley's on all of them and the primers were blown out on all but 2.

I've read that this ammo is considered "warm". Had I known the outcome, obviously I would have taken a reading after a round or two. Will a stiffer recoil spring help out here or do I need an aftermarket barrel as well?

I don't want to spend a lot of coin on an old gun that runs great with Georgia Arms, federal, Hornandy, etc.. I would rather take that money and put it towards a new Gen 3 or hopefully soon a Gen 4. Thoughts and/or suggestions? Thank you and I am going to attempt to attach pics. Last time I tried it said "exceeded quota size" ???

glock20c10mm
12-11-2011, 12:23
I'm waiting to see the pics to see what you mean when you say; "...primers were blown out..."

JimIsland
12-11-2011, 12:34
I'm waiting to see the pics to see what you mean when you say; "...primers were blown out..."

Sending PM. Thanks

_The_Shadow
12-11-2011, 14:09
When or has was the recoil spring changed? I would invest in a new recoil spring of possibly extra power? Should help maintain lock up a little longer, provided the locking block is not worn. Keeping the slide locked a tad longer may help keep primers inside and lessen the smiles, however a barrel with better chamber support is what will support the casing better.

Your barrel and slide may be unlocking too early for the amout of impulse you are seeing with that ammo leading to smiles.

freakshow10mm
12-11-2011, 14:31
Primers should not be blowing out. That's a sign of over pressure ammunition.

arushus
12-11-2011, 14:44
While shootin some underwood 180gr fmj's a few days ago, I found one case with the primer missing from it while I was picking up my brass. No glocksmile or bulge since I was using my LWD barrel, which has terrific support, but it causes feeding issues...oh well, guess I cant have my cake and eat it too...seriously tho, whats the point of having cake if you cant eat it?

glock20c10mm
12-11-2011, 14:54
Sending PM. Thanks
Thanks for allowing me to share the pics you send in the email.

Here are pics of the brass fired from Jim's G20 Gen 2 -

http://i154.photobucket.com/albums/s271/glock20c10mm/Ammo%20Pics/2011-12-11_13-00-49_647-crop.jpg

http://i154.photobucket.com/albums/s271/glock20c10mm/Ammo%20Pics/2011-12-11_12-59-53_636-crop.jpg

First, I would say that at least some Generation 2 G20s were known for having less chamber support than current production models.

Second, I would say over the course of Double Tap 10mm history there have been inconsistencies with their ammo. In the past we used to get advertised velocity, then later not even close. Last chronograph results of the DT 10mm 165gr Gold Dot loads (which they don't make anymore) averaged 1254fps (they were advertised at 1400fps), and the current DT 10mm 165gr Golden Sabers averaged 1240fps (they are advertised at 1400fps). Then there are others who still claim to get much closer to DT box flap claims. Bottom line, I don't what kind of quality control Mike McNett is running over at Double Tap, but my faith in it, for one, is bigtime lacking. So who knows if you got hotter or weaker stuff, and then in possible conjunction with a Gen 2 G20 that may not have the chamber support we've currently grown accustomed to.

In regard to DT ammo, here's another post put up a mere 13 days ago -
After a Double Tap 10mm blew in half in my brand new Kimber, locking up the pistol and rendering me unarmed, I ran the rest through my 610.

I sent the case and the rest of the box to Mike McNett and have never ever heard back from him again.

Not even a scanned finger.:steamed:

Nothing.

Guess what I have ordered from him since?
And then add in the possibility of what _The_Shadow pointed out with your "older" (don't know what round count may be through it) Gen 2 G20 maybe having a weak recoil spring...and things just start looking possibly exponentially reasoned out.

Jim, following is a pic of my G29 chamber support. How does your Gen 2 G20 compare with a round dropped in the tube for comparison? Any discernable differences?

http://i154.photobucket.com/albums/s271/glock20c10mm/G29/P1060295-crop.jpg

http://i154.photobucket.com/albums/s271/glock20c10mm/G29/P1060293-crop.jpg

glock20c10mm
12-11-2011, 14:55
Primers should not be blowing out. That's a sign of over pressure ammunition.
I was thinking the same. I've had the smilies and some flattened primers from DT, but never had a primer come out of the case or even be loose.

glock20c10mm
12-11-2011, 15:01
While shootin some underwood 180gr fmj's a few days ago, I found one case with the primer missing from it while I was picking up my brass.
I been wondering just what brand of primers them ammo makers are using individually. I know Mike McNett was always big on CCI when he used to post around here, but that doesn't prove he uses the same in his factory ammo.

And then what primers is Underwood using?

Either way, I guess it doesn't matter, I would expect a little flattening from primers way before they're falling right out of the cases! Seems like way overpressure to me even if some Gen 2 G20 barrels didn't have the best case support compared to now in the Gen 3 G20.

_The_Shadow
12-11-2011, 15:12
Looking at the casing (stamp McNett) that is a very high pressure round with the primer blown and a casing tear starting, but also looking at the amount of smile from the lack of support tells me the cartridge was moving back out of the chamber while pressure was still very high. Primer being blown out may have unlocked the slide.

One other possibility is bullet setback on a round, which was already at the upper limits of performance (if not an over charge) and that would increase pressures aswell. More than one round did this so I lean more toward the next possibility.

That possibility is that there was an over charge of powder or even the wrong powder for the application!

These need to be investigated further to examine what is actually happening. Setting up a return to McNett might get you replacement ammo, but we may never learn the true cause...

Taterhead
12-11-2011, 15:18
I would not shoot any ammo that looked like that. Yikes. We have seen a couple of pics lately if gen 2s that are, I guess you would say cavernous, at the six o'clock position. But I am leaning toward this being an ammo problem. I agree with freakshow on this. Looks like a qc problem at McNett's.

glock20c10mm
12-11-2011, 15:37
These need to be investigated further to examine what is actually happening. Setting up a return to McNett might get you replacement ammo, but we may never learn the true cause...
And if you do set up the return, request "delivery confirmation" as I've notice numerous cases over the past couple years now of Double Tap 100% ignoring people's requests/concerns/issues. Don't know to what extent delivery confirmation would help anything in the end, I just feel like somehow it may be a step in the right direction.

JimIsland
12-11-2011, 16:02
And if you do set up the return, request "delivery confirmation" as I've notice numerous cases over the past couple years now of Double Tap 100% ignoring people's requests/concerns/issues. Don't know to what extent delivery confirmation would help anything in the end, I just feel like somehow it may be a step in the right direction.


Thanks a lot you guys. Had I not joined "10 Ring" :

a) I would not have been collecting my brass
B) Wouldn't have a clue what 'smile" is
c) I would have ignorantly shot the rest of the DT box and who knows what would have happened.

Sir, if you don't mind, I will take a pic of my support chamber after dinner.

Much appreciated guys.

B.Reid
12-11-2011, 16:45
Something is wrong there. You still should get a new recoil spring. I tend to buy extra power springs.

_The_Shadow
12-11-2011, 16:53
Jim, had not the primer blown out you might would have seen a case rupture that could have sent a high pressure jet of gases down the magazine well...this could wreck the magazine, frame and even your hand could be injured in this kind if over pressure situation. Glad you shared your experiences so others can learn from it.

attrapereves
12-11-2011, 16:58
Haven't we seen this before? A DoubleTap round that has a serious problem...

A lot of times, it's the gun, but something becomes fishy when multiple people begin having problems with a certain manufacturer of ammo.

I've shot a few of the 155grn SilverTips (rated at around 1425fps) I bought from SwampFox and the casings looked the same as Georgia Arms 180grn FMJ casings. No smiles or blown primers, just a tiny bulge.

10 fan
12-11-2011, 18:17
I'm new to this and any form and have learned alot.I have a Gen 1 G20 I bought new in 91 and have never had a problem.I never saved or checked my brass so don't know what it looked like.I would guess the first 8 or 900 rounds were norma full strenth and then what I could find.I still shoot it now and then and have put some DT thru it, but never looked at my brass.I now save my brass and have 2000 so I will look at it.most of it is BVAC so not to hot. I shoot my Gen3 G20,G29 now and no trouble with eather,but here alot about chamber support.

arushus
12-11-2011, 18:29
I'm new to this and any form and have learned alot.I have a Gen 1 G20 I bought new in 91 and have never had a problem.I never saved or checked my brass so don't know what it looked like.I would guess the first 8 or 900 rounds were norma full strenth and then what I could find.I still shoot it now and then and have put some DT thru it, but never looked at my brass.I now save my brass and have 2000 so I will look at it.most of it is BVAC so not to hot. I shoot my Gen3 G20,G29 now and no trouble with eather,but here alot about chamber support.

Im going to assume you meant Gen 2?

JimIsland
12-11-2011, 18:52
I'm new to this and any form and have learned alot.I have a Gen 1 G20 I bought new in 91 and have never had a problem.I never saved or checked my brass so don't know what it looked like.I would guess the first 8 or 900 rounds were norma full strenth and then what I could find.I still shoot it now and then and have put some DT thru it, but never looked at my brass.I now save my brass and have 2000 so I will look at it.most of it is BVAC so not to hot. I shoot my Gen3 G20,G29 now and no trouble with eather,but here alot about chamber support.

Yup....same here. The snappiest ammo I've shot out of mine was some recently purchase G.A. hollow point 165g. I can't ever remember having a FTF or FTE with this remarkable gun. I think for the time being, I'll replace the recoil spring and revert to GA stuff.

oceanbob
12-11-2011, 19:54
Jim...glad you're ok....If you have any Double Tap left, I would wear a pair of leather gloves and safety glasses when shooting them. Seriously.

Also, get yourself at least a 20 pound spring. That weight will run anything. I had a Gen 2 Glock 2 back in 1992 or 1993 but I don't know how good the chamber support was. (I was reloading .45 back then, not 10MM) Sold that weapon in 1995.

I really think if you had a new spring and new barrel you would be fine with anything, including Buffalo Bore. :supergrin:

Be well, Bob

JimIsland
12-11-2011, 21:12
Jim...glad you're ok....If you have any Double Tap left, I would wear a pair of leather gloves and safety glasses when shooting them. Seriously.

Also, get yourself at least a 20 pound spring. That weight will run anything. I had a Gen 2 Glock 2 back in 1992 or 1993 but I don't know how good the chamber support was. (I was reloading .45 back then, not 10MM) Sold that weapon in 1995.

I really think if you had a new spring and new barrel you would be fine with anything, including Buffalo Bore. :supergrin:

Be well, Bob

Thanks Bob, I have 40 left but will not shoot them. I'm going to change out the spring and test 1 bullet and see if anything changes. Also going to the LGS and check out a Gen 3 G20:whistling:

10 fan
12-11-2011, 23:42
Im going to assume you meant Gen 2?
I thought 1991 would be a gen 1,I'll have to look when I get home in a few days.I have shot alot of DT in the g20,g29 Gen3 and have never had a problem.I still have 500 rounds of 180gr. bonded defense I bought 2 or 3 years ago(which is my carry ammo)and 3 or 4 hundred of 180gr. fmj target ammo. I have heard alot about DT in this forum(90% not good) so I ordered a chronograph to check all my ammo. Most of my shooting has been BVAC 180gr. FMJ as it has been the best price and I have had no problems in the last 8000 rounds. I can only remember 1 FTF

arushus
12-12-2011, 01:16
I thought 1991 would be a gen 1,I'll have to look when I get home in a few days.I have shot alot of DT in the g20,g29 Gen3 and have never had a problem.I still have 500 rounds of 180gr. bonded defense I bought 2 or 3 years ago(which is my carry ammo)and 3 or 4 hundred of 180gr. fmj target ammo. I have heard alot about DT in this forum(90% not good) so I ordered a chronograph to check all my ammo. Most of my shooting has been BVAC 180gr. FMJ as it has been the best price and I have had no problems in the last 8000 rounds. I can only remember 1 FTF

The last gen 1's were made in 88-89...the only gen 1 glocks are the 17, 17L, 18, and a few prototype 19's...no 20's were made in a Gen 1 frame...

Ive shot about 200 rounds of bvac, never had a problem with it either! It is cheap, the brass is reloadable, and it doesnt seem to have too many failures. Only thing that stops me from buying more of it is them lying about the velocity...its not too much hotter than .40sw...

21Carrier
12-12-2011, 01:49
Jim, when was that Double Tap ammo purchased? Is it old or new? From the look of your brass, it seems you have one of the "wide-open" Gen2 G20 chambers. This is only the second I've seen, but apparently this is real. There was another guy who blew his Gen2 G20 up with old DT 165gr Gold Dots. His brass looked IDENTICAL to yours. A normal Glocksmile forms a nice semi-circle, like this:

http://i1104.photobucket.com/albums/h329/21Carrier/IMG_1993.jpg

As you can see, a "normal" Glocksmile has a semi-circular shape to it. Yours (and the other guy's) had a cloverleaf type shape. This seems to be because Glock opened up the chambers more than usual on some guns. They did some cutting around the feed ramp, and especially in the 5 and 7 o'clock positions. Those belled areas (at 5 and 7 o'clock) leave huge unsupported areas, and make brass failure more likely. However, all that being said, primers do not blow out of new brass unless things are getting SERIOUS. I have shot some pretty stupid loads through my 10mms, and nearly blown one up. I have never had a primer even back out a little, even with old, loose brass.

I think this is the result of over-pressure ammo being compounded by a barrel with horrendous support. I would do two things. First, if that ammo is new, I would send it and the cases back to Double Tap. Second, I would order a new G20 barrel. I'm not the biggest proponent of aftermarket barrels, but they will definitely give you the most support. I would just get a factory Glock replacement barrel. Anyone can try to blame this on a number of different things, but I doubt ANYONE will argue that the ammo was the main problem. Yes, the barrel may have made the problem worse, and a really weak spring may have allowed early unlocking, but the ammo was the real problem. I would update your barrel and springs to new, and call it a day. Despite all the hype about needing aftermarket barrels to shoot hot loads, you just don't ever see this type of stuff happening. When you do, it's always got one common thread: suspect ammo. Either some idiot (like me) over-charged a round, or you got the odd box of super hot factory stuff. I'm waiting to see your barrel, but I have a feeling it will look like the other guy's, which looked like someone handed a chimp the barrel and a Dremel.

alwaysshootin
12-12-2011, 05:08
My first G20 was a 2nd Gen, and fired rounds, looked like the worst of those pictured in this thread! An after market barrel, with great chamber support, cured all the bulging problems. Not a gambling man, but would almost bet money, if you dropped in a Lone Wolf barrel in your 20, there would not be a problem with the DT ammo.

ALBin517
12-12-2011, 07:38
Shadow - a smile came to my face and my eyes instantly darted left to read your location when I saw the "might would" in your post.

I moved from Tallahassee to Michigan about a decade ago and most folks around here cannot correctly use "might would" in casual conversation.

JimIsland
12-12-2011, 08:14
Jim, when was that Double Tap ammo purchased? Is it old or new? From the look of your brass, it seems you have one of the "wide-open" Gen2 G20 chambers. This is only the second I've seen, but apparently this is real. There was another guy who blew his Gen2 G20 up with old DT 165gr Gold Dots. His brass looked IDENTICAL to yours. A normal Glocksmile forms a nice semi-circle, like this:

http://i1104.photobucket.com/albums/h329/21Carrier/IMG_1993.jpg

As you can see, a "normal" Glocksmile has a semi-circular shape to it. Yours (and the other guy's) had a cloverleaf type shape. This seems to be because Glock opened up the chambers more than usual on some guns. They did some cutting around the feed ramp, and especially in the 5 and 7 o'clock positions. Those belled areas (at 5 and 7 o'clock) leave huge unsupported areas, and make brass failure more likely. However, all that being said, primers do not blow out of new brass unless things are getting SERIOUS. I have shot some pretty stupid loads through my 10mms, and nearly blown one up. I have never had a primer even back out a little, even with old, loose brass.

I think this is the result of over-pressure ammo being compounded by a barrel with horrendous support. I would do two things. First, if that ammo is new, I would send it and the cases back to Double Tap. Second, I would order a new G20 barrel. I'm not the biggest proponent of aftermarket barrels, but they will definitely give you the most support. I would just get a factory Glock replacement barrel. Anyone can try to blame this on a number of different things, but I doubt ANYONE will argue that the ammo was the main problem. Yes, the barrel may have made the problem worse, and a really weak spring may have allowed early unlocking, but the ammo was the real problem. I would update your barrel and springs to new, and call it a day. Despite all the hype about needing aftermarket barrels to shoot hot loads, you just don't ever see this type of stuff happening. When you do, it's always got one common thread: suspect ammo. Either some idiot (like me) over-charged a round, or you got the odd box of super hot factory stuff. I'm waiting to see your barrel, but I have a feeling it will look like the other guy's, which looked like someone handed a chimp the barrel and a Dremel.

Thanks Carrier...I was hoping you would chime in as well. The DT ammo was purchased 2 weeks ago and I have 40 left from the box of 50. My son noticed on the last two rounds that I fired, something flying out of the gun. When I picked up my casings is when i realized that I got lucky and this could have been really bad. This G20 is by far my favorite, most reliable, accurate shooting handgun I've ever owned. I would have had a bad case of the butt hurt if it would have kaboomed.:steamed:
Last night when I looked at the spent casings, I also noticed that most of them were out of round. Almost oblong if you will...yikes.

So I'm going to order a new stock barrel right now. What kind of recoil spring should I go with and how many pounds? I don't want to get too heavy a spring and create a problem that never existed using "normal" ammo. Thanks for help bud. PM sent.

Taterhead
12-12-2011, 08:29
My first G20 was a 2nd Gen, and fired rounds, looked like the worst of those pictured in this thread! An after market barrel, with great chamber support, cured all the bulging problems. Not a gambling man, but would almost bet money, if you dropped in a Lone Wolf barrel in your 20, there would not be a problem with the DT ammo.


Hi alwaysshootin, I am not much of a gambler, but I will almost take you up on your almost wager. :supergrin:


I am trying to think of a scenario where blown primer pockets is explained by lack of chamber support.

Like freakshow10mm said in an earlier post, blown primers are a sign of excess pressure. He is an ammo manufacturer so has some credibility on the issue.

10 fan
12-12-2011, 10:37
The last gen 1's were made in 88-89...the only gen 1 glocks are the 17, 17L, 18, and a few prototype 19's...no 20's were made in a Gen 1 frame...

Ive shot about 200 rounds of bvac, never had a problem with it either! It is cheap, the brass is reloadable, and it doesnt seem to have too many failures. Only thing that stops me from buying more of it is them lying about the velocity...its not too much hotter than .40sw...
My mistake on the generation,thought the first ones made were gen 1. One of the many things I've learned here is most add. velocitys are not true,which is why I ordered a chrono.I'll be checking all of my ammo when I get back to L.A.I guess I don't get out much as I thought DT was my only choice besides low vel. stuff. The more I read the more I worry about DT ammo I have. Don't know if I got lucky (about 1200 rounds of DT) or got a good batch.My carry ammo is DT 180gr. bonded defense which they don't make anymore,and 155gr.barnes or 200 gr. hc for woods protection. I'll be checking ammo this weekend.

alwaysshootin
12-12-2011, 10:37
Hi alwaysshootin, I am not much of a gambler, but I will almost take you up on your almost wager. :supergrin:


I am trying to think of a scenario where blown primer pockets is explained by lack of chamber support.

Like freakshow10mm said in an earlier post, blown primers are a sign of excess pressure. He is an ammo manufacturer so has some credibility on the issue.

This is just my thinking, and probably wrong but here it goes. The only reason a bullet, from pressure, goes down the barrel is, it is the path of least resistance. The pressure builds, and pushes the bullet, out of the brass, allowing the bullet and gasses to escape down the barrel. Now, by having an unsupported chamber, plus a loose chamber, allowing the brass to expand, outward, more so, than on a tight chamber and slightly rearward, with the loose tolerances in the feed ramp area. So expanding gases, not only going down the barrel, pushing the bullet in front of it, You have expanding gases, pushing a bullet, expanding the brass circumference, and bulging towards the rear," the smiley effect", I can see how primers can be dislodged. Like I said, I'm probably wrong, but I can see it happening, and feel, that a tight chamber, may relieve the problems occurring. If expanding gasses are going in three opposing directions, versus one, down the barrel, blown primers, blown brass, smileys, can happen! By the way, this scenario can cause excess pressure!

ModGlock17
12-12-2011, 11:00
Wow. Depends on when you purchased, your DT ammo can be one thing or another !

'Tis the reason to tell your other half that you need money for reloading equipment. At least you have some control.

But before jumping on the ammo's "case", no pun intended, throw in a good and well supported aftermarket KKM barrel with a 20# spring, if you dare to shoot those ammo again.

I would take one of those DT, pull the bullet, measure the charge weight and bullet weight, etc. find out which powder was used. We've got enough data to tell whether the charge was high.

I would also use a garden variety round from someone, like GeorgiaArms or BVAC and see what the fired cased look like.

B.Reid
12-12-2011, 11:13
This is just my thinking, and probably wrong but here it goes. The only reason a bullet, from pressure, goes down the barrel is, it is the path of least resistance. The pressure builds, and pushes the bullet, out of the brass, allowing the bullet and gasses to escape down the barrel. Now, by having an unsupported chamber, plus a loose chamber, allowing the brass to expand, outward, more so, than on a tight chamber and slightly rearward, with the loose tolerances in the feed ramp area. So expanding gases, not only going down the barrel, pushing the bullet in front of it, You have expanding gases, pushing a bullet, expanding the brass circumference, and bulging towards the rear," the smiley effect", I can see how primers can be dislodged. Like I said, I'm probably wrong, but I can see it happening, and feel, that a tight chamber, may relieve the problems occurring. If expanding gasses are going in three opposing directions, versus one, down the barrel, blown primers, blown brass, smileys, can happen! By the way, this scenario can cause excess pressure!

Every time you fire a round the primer starts to back out. Then the case hits the bolt face resetting the primer. I think in this case te slide is moving back so fast that contact between the bolt face and case is broken.

ModGlock17
12-12-2011, 11:24
Every time you fire a round the primer starts to back out. Then the case hits the bolt face resetting the primer. I think in this case te slide is moving back so fast that contact between the bolt face and case is broken.

Firing a garden variety round, Georgia Arms, then look at the case... would narrow that down?

_The_Shadow
12-12-2011, 11:25
Shadow - a smile came to my face and my eyes instantly darted left to read your location when I saw the "might would" in your post.

I moved from Tallahassee to Michigan about a decade ago and most folks around here cannot correctly use "might would" in casual conversation.

"might would"...It is something which has to do with the uncertainties of when dealing with unkowns. Clearly that cartridge shows a definite split/tear which started. It was ever so close to total case failure/blow out, having seen the results and damage done by incidents where the case did rupture, it "might would" have been very serious.:shocked:

I like being on the safe side of things, in this incident, I would have pulled some of those rounds, investigated the powder charge weight first and far most, tried to identify what powder it is being used, compared it to known samples, and loading data to grasp a better understanding of the loading.

The only DT ammo I purchased was his 9x25Dillon to test my 9x25Dillon conversion barrel I bought from McNett for my S&W1006. I actually pulled down his loads, documented the charge weights of the cartridges for each bullet weight. At the time the powder was unknown to me, but heavy discussion, sharing of pictures and information, led me to a purchase of powder which ended up being what he used...therefore I was able to duplicate the cartridges for myself and personal use. Being a handloader and having the tools and dies to to work with, becomes a powerful asset to understanding what is involved.

Handloading for me is a passion, that helps me enjoy the shooting even more! :cool:

arushus
12-12-2011, 11:37
Sorry, off topic I know, but shadow's post about figuring out what powder mcnett uses got me curious..do bullet manufacturers have access to powder that the public does not? Or do they use the exact same stuff available to us?

JimIsland
12-12-2011, 11:44
Wow. Depends on when you purchased, your DT ammo can be one thing or another !

'Tis the reason to tell your other half that you need money for reloading equipment. At least you have some control.

But before jumping on the ammo's "case", no pun intended, throw in a good and well supported aftermarket KKM barrel with a 20# spring, if you dare to shoot those ammo again.

I would take one of those DT, pull the bullet, measure the charge weight and bullet weight, etc. find out which powder was used. We've got enough data to tell whether the charge was high.

I would also use a garden variety round from someone, like GeorgiaArms or BVAC and see what the fired cased look like.

Good advise, although I don't I want to venture out into the aftermarket barrel scene.(yet) I am ordering a new stock barrel however I'm open for suggestions on the recoil spring.The stock one feels rather weak in comparison to a gen 3 spring like I have on my G26 and G30. What company makes a 20# spring and should I upgrade the plastic guide tube to a steel one as well??

after a new recoil spring and barrel goes in, I will test fire 1 bullet with leather gloves and my motorcycyle helmet!!lol

BTW....I ran 10 Georgia Arms before and after shooting the DT. It was the 165 grain hollow point and felt pretty snappy but I'm sure is "warm" compared to what a lot of you folks are used to.
Thanks again.....

glock20c10mm
12-12-2011, 11:49
Good advise, although I don't I want to venture out into the aftermarket barrel scene.(yet) I am ordering a new stock barrel however I'm open for suggestions on the recoil spring.The stock one feels rather weak in comparison to a gen 3 spring like I have on my G26 and G30. What company makes a 20# spring and should I upgrade the plastic guide tube to a steel one as well??

after a new recoil spring and barrel goes in, I will test fire 1 bullet with leather gloves and my motorcycyle helmet!!lol

BTW....I ran 10 Georgia Arms before and after shooting the DT. It was the 165 grain hollow point and felt pretty snappy but I'm sure is "warm" compared to what a lot of you folks are used to.
Thanks again.....
Wolff Gunsprings

http://www.gunsprings.com/index.cfm?page=items&cID=1&mID=5#109

The site should answer at least some of your questions.

_The_Shadow
12-12-2011, 11:52
JimIsland, If I remember correctly the older G-20's had some differences in the barrels from the newer models and they were not the same cut and fit. Therefore you may want to investigate the use of a aftermarket barrel and the date of your pistol before just buying the repalcement barrel!

Edited; It may be the slides which are different from Gen 2 and gen 3 G-20's

TreyG-20
12-12-2011, 12:03
Sorry, off topic I know, but shadow's post about figuring out what powder mcnett uses got me curious..do bullet manufacturers have access to powder that the public does not? Or do they use the exact same stuff available to us?
I have wondered about this myself before, but i dont have that answer. I would assume most factory ammo is the same stuff we can buy. Then again i remember reading that Mike Willard use to blend his powders to get some of his loadings. Maybe thats what DT might be doing. But i doubt bigger companies like winchester, federal and remington do that.

TreyG-20
12-12-2011, 12:05
JimIsland, If I remember correctly the older G-20's had some differences in the barrels from the newer models and they were not the same cut and fit. Therefore you may want to investigate the use of a aftermarket barrel and the date of your pistol before just buying the repalcement barrel!
No they are interchangable. I could switch barrels from my Gen 2 and gen 3 with no problems. And aftermarket ones are also just drop in.

ModGlock17
12-12-2011, 12:10
BTW....I ran 10 Georgia Arms before and after shooting the DT. .....

I am curious. Was the GA case appeared normal?

I've experimented with recoil spring assembly mfgrs on the G20: Sprinco, Wolf, ISMI (sp?).

Sprinco was expensive, but softest recoil. They got dual springs where the primary spring was 17# and a heavier secondary protects the frame. It had FTFeed off and on. Changed to 15# and it was less, but still occurred and annoying. FTFeed occurred on both KKM and LWD barrels, both of 6" length.

Wolf steel guide rod and 20# or 22# spring was flawless with 6" KKM barrel, but had FTFeed if I use 6" LWD barrel. Most importantly, this KKM and 180gr Nosler at 1,300fps or so, gave me the most accurate gun/ammo combination for my G20, and very reliable (which I think, is a matter of statistics).

ISMI steel guide rod and 20# or 22# spring was flawless with both 6" barrels in terms of reliability. BUT, it was less accurate than the Wolf system. AFter some experimenting, I discovered that the ISMI, using either springs, fails to push the slide into battery with sufficient force to lock the barrel into Slide Lock position (I use MatchGrade SLock sold by Mr Graham) with more authority. It seems the flat spring design was a tad weak, near the end of its expansion where as the regular spring is stronger, given the same weight. So my shots scatters more. As soon as I switch to Wolf, it gets back accuracy.

Those are my findings. It could be just due to my gun's mfgr tolerance.

JimIsland
12-12-2011, 14:03
I am curious. Was the GA case appeared normal?

I've experimented with recoil spring assembly mfgrs on the G20: Sprinco, Wolf, ISMI (sp?).

Sprinco was expensive, but softest recoil. They got dual springs where the primary spring was 17# and a heavier secondary protects the frame. It had FTFeed off and on. Changed to 15# and it was less, but still occurred and annoying. FTFeed occurred on both KKM and LWD barrels, both of 6" length.

Wolf steel guide rod and 20# or 22# spring was flawless with 6" KKM barrel, but had FTFeed if I use 6" LWD barrel. Most importantly, this KKM and 180gr Nosler at 1,300fps or so, gave me the most accurate gun/ammo combination for my G20, and very reliable (which I think, is a matter of statistics).

ISMI steel guide rod and 20# or 22# spring was flawless with both 6" barrels in terms of reliability. BUT, it was less accurate than the Wolf system. AFter some experimenting, I discovered that the ISMI, using either springs, fails to push the slide into battery with sufficient force to lock the barrel into Slide Lock position (I use MatchGrade SLock sold by Mr Graham) with more authority. It seems the flat spring design was a tad weak, near the end of its expansion where as the regular spring is stronger, given the same weight. So my shots scatters more. As soon as I switch to Wolf, it gets back accuracy.

Those are my findings. It could be just due to my gun's mfgr tolerance.

The G.A ammo looks fine. As does everything else I've ever run throught it. Corbon Powerball, Hornandy, Winchester, Blazer, UMC, Winchester X, etc..
Great advise on the spring and barrel stuff!! I'm going to do some research tonight over a Gentleman Jack!

arushus
12-12-2011, 14:46
The only spring I have experience with is an ISMI 22lb spring o a lwd ss guide rod...I really like it, but I wish Id gone with 24lb now. Brass still gets flung twenty feet with the aftermarket spring. Im thinking modglock is on to something with his theory about them not being quite as strong...Im not doggin them at all! I love my spring! It just still flings the brass pretty far, granted, it doesnt go as far as it would with the stock spring.
That being said, Im sticking with the ISMI brand when I buy a 24lb spring, Ive read a lot of issues with wolff recoil springs being too long, or not reliable, etc..

JimIsland
12-12-2011, 16:52
The only spring I have experience with is an ISMI 22lb spring o a lwd ss guide rod...I really like it, but I wish Id gone with 24lb now. Brass still gets flung twenty feet with the aftermarket spring. Im thinking modglock is on to something with his theory about them not being quite as strong...Im not doggin them at all! I love my spring! It just still flings the brass pretty far, granted, it doesnt go as far as it would with the stock spring.
That being said, Im sticking with the ISMI brand when I buy a 24lb spring, Ive read a lot of issues with wolff recoil springs being too long, or not reliable, etc..

Any problems shooting "cool" range ammo with the 22# spring?

Taterhead
12-12-2011, 17:22
Every time you fire a round the primer starts to back out. Then the case hits the bolt face resetting the primer. I think in this case te slide is moving back so fast that contact between the bolt face and case is broken.

You are right about primers working out a bit, and severe instances of this can cause excessively flattened primers. This is often confused as an excess pressure situation when actually be a headspace or other malfunction. However they will be re-seated when gases force the case against the breach face.

Perhaps someone could help me here, but since the case acting backwards against the breach face is what causes the slide to travel, how could the slide travel backward fast enough to outrun the rearward travel of the case and thus getting separation. That seems to be a requirement if we were to conclude that the primers popped due to a reason other than a weakened primer pocket caused by a pressure event. In other words, how would the breachface move away from the case head while still under pressure? At a minimum, the slide would need to unlock while under significant pressure. Possible. But I am still struggling with how the slide would move backward at a faster rate than the case.

Trying to seat new primers would give clues about whether gasses from excess pressure stretched the primer pocket such that the caseprimers let go of the brass upon brass ejection. Looking at the condition of that massive near-rupture of the case, I would be inclined to look to the ammo as a problem.

harrygunner
12-12-2011, 18:48
I'm surprised the words "Double Tap" were not on the bottom of the cases. They're on every round I bought in 10mm, .40 S&W and .45 ACP.

When did they stop marking their brass with the company name?

_The_Shadow
12-12-2011, 19:01
The catridge case expands to fit the chamber if the load is of significant pressure, if the pressuer of the fired round is too low the casing will not expand enough and carbon and soot will pass between the casing and chamber walls.

When the cartridge is fired, the bullet is acting on the barrel in such a way to hold it forward and help maintain slide lock. If the casing is shorter than the chamber this allows more room for case movement, primer movement.

However things can and do happen, excessive pressure at the point of unlock will still be acting on the casing and primer cup as the slide starts movement. In extreme pressure events, are the slide/barrel lock being over come before the bullet exits the barrel? It should not...But! Only high speed photography of the event, played back in slowmotion play back would show if it is happening.

JimIsland
12-12-2011, 20:21
[QUOTE=harrygunner;18278353]I'm surprised the words "Double Tap" were not on the bottom of the cases. They're on every round I bought in 10mm, .40 S&W and .45 ACP.

When did they stop marking their brass with the company name?[/QUOTE

The 50 count box I recently purchased had: "10mm Mcnetts" on the casings.

blastfact
12-12-2011, 20:55
I would suspect the massive bulging of the brass caused the primer pocket to deform. Thus causing a slight gas leak and spitting the primer out.

That is a scary looking piece of brass. I would bet it's bulging more than half way around.
and that clover leaf pattern is way scary. I would not shoot that barrel!

arushus
12-13-2011, 02:04
Any problems shooting "cool" range ammo with the 22# spring?

None whatsoever! It is a very good general purpose spring. I even shoot the weakest .40sw ammo I can find, tulammo, through my conversion barrel using the 22lb ismi spring. The cases land about a foot or two away, but it cycles reliably every time!
That being said, my slide runs very smoothly on my frame, it didnt at first, but after a few hundred rounds, it smoothed way out, so it doesnt take much force at all to cycle the slide...

21Carrier
12-13-2011, 06:22
Jim, I think you're doing the right thing getting a Glock replacement barrel and new springs. Still, I will be happy to see your barrel, and I would suggest you send me that photo before ordering your new barrel, just to make sure. However, after seeing your brass, I'm 99.9% sure you have an over-worked (opened up too much) chamber.

As far as springs go, I would first buy a new Glock spring. Then, you could also get some stronger ones for the range. A stronger spring will reduce battering (if that's even really a legitimate problem with a Glock), reduce the distance your brass flies, and might delay breech unlocking (this is debatable). Also, the late Mike Willard used to say that the main benefit, in his opinion, was that the extra power assured the round was slammed home, and the gun fully returned to battery. That prevents firing while slightly out of battery. However, be aware that heavier springs can cause slight feeding issues. I've used 17lb, 21lb, and 23lb Wolff springs (and Wolff steel guide rod) in my G29, and experienced some minor feeding issues with high-power loads with the heavy springs (that's why I think you should also get a new factory spring, as I would never carry a heavier spring). The minor feeding issues don't stop me from using them at the range. They work 99.9% of the time, and keep my brass from reaching orbit. I also use ISMI springs (with LWD stainless guide rod) in my G20LS, and have used the 17lb and 20lb with no issues. I also have a 22lb, but I've never used it. I would recommend the Wolff 20lb or 22lb and steel guide rod, but the ISMI springs should be fine as well.

You are right about primers working out a bit, and severe instances of this can cause excessively flattened primers. This is often confused as an excess pressure situation when actually be a headspace or other malfunction. However they will be re-seated when gases force the case against the breach face.

Perhaps someone could help me here, but since the case acting backwards against the breach face is what causes the slide to travel, how could the slide travel backward fast enough to outrun the rearward travel of the case and thus getting separation. That seems to be a requirement if we were to conclude that the primers popped due to a reason other than a weakened primer pocket caused by a pressure event. In other words, how would the breachface move away from the case head while still under pressure? At a minimum, the slide would need to unlock while under significant pressure. Possible. But I am still struggling with how the slide would move backward at a faster rate than the case.

Trying to seat new primers would give clues about whether gasses from excess pressure stretched the primer pocket such that the caseprimers let go of the brass upon brass ejection. Looking at the condition of that massive near-rupture of the case, I would be inclined to look to the ammo as a problem.

I don't think that's possible. It just doesn't make sense. The only way I see that happening is if the fired round started the recoil cycle, then expanded so much it got partially stuck in the chamber. Then, if the extractor lost the grip on the rim, it could allow the primer to blow out, but pressures should be low enough at that point to prevent it.

I would suspect the massive bulging of the brass caused the primer pocket to deform. Thus causing a slight gas leak and spitting the primer out.

That is a scary looking piece of brass. I would bet it's bulging more than half way around.
and that clover leaf pattern is way scary. I would not shoot that barrel!

I think you're right. Like Jim said above, his brass was actually oblong. I remember seeing that with some of Burien's brass when he used too much Titegroup with Barnes bullets (to see it, look at his stickied thread at the top of the 10 Ring, called something like "Over Pressure Looks Like This"). If a piece of brass is subjected to enough pressure, the entire case head deforms (see Burien's pics), opening up the primer pocket, and allowing it to pretty much just fall out. I think that's what happened here.

JimIsland
12-13-2011, 09:03
Carrier, as stated in my email, I will get better pics for you to look at with a real camera. Thanks for your help.

here is the steps I've taken:

Ordered: stock recoil spring, stainless guide rod, 20#,22# and 24# ISMI springs. I am going to go out to my buddy's farm and do some experimenting. I will of course have my safety gear and leather golves on as well as wait to see what Carrier says about my chamber support or lack of.

Also since I "punished" her and she didn't kaboom on me, I rewarded her with some new Big Dot 24/7 night sights!

glock20c10mm
12-13-2011, 12:44
Carrier, as stated in my email, I will get better pics for you to look at with a real camera.
It would be great if you could post the pics right here in the thread too so we can all see and/or compare to our own setups.

JimIsland
12-13-2011, 14:47
It would be great if you could post the pics right here in the thread too so we can all see and/or compare to our own setups.

I tried. For some reason when went to attach the pic, I got a message that said I had exceeded my size quota. I think it might have something to do with using my Droid at 8MP. I'll figure it out when I get time. Carrier is going to post the pic of my barrel as well.

ModGlock17
12-13-2011, 15:47
I tried. For some reason when went to attach the pic, I got a message that said I had exceeded my size quota. I think it might have something to do with using my Droid at 8MP. I'll figure it out when I get time. Carrier is going to post the pic of my barrel as well.


Make your pictures smaller, Jim. May be replacing the one you already posted, with smaller size. It would make it faster for us to load the web page, too.

glock20c10mm
12-13-2011, 18:58
I tried. For some reason when went to attach the pic, I got a message that said I had exceeded my size quota. I think it might have something to do with using my Droid at 8MP. I'll figure it out when I get time. Carrier is going to post the pic of my barrel as well.
Cool!:thumbsup:

Not sure if this sounds "greek" to you, but using photobucket.com has never given me an issue. After you upload any pics to photobucket is makes it real easy for you to copy/paste the "" code from there to here in your new posts. GlockTalk does limit you to like 5 pics per post, as long as you don't go over that amount you should be okay. If it still says you have exceeded the quota size than just delete one pic at a time till it lets you post. I've posted many pics at everything from 3 mega pixels to over 10 mp without issue, and photobucket seems to resize the really large ones to a smaller size anyway. Feel free to PM me if you want further details.