Bought a Gen 4 G20 Today!

[GunBugBit]

Yes, I was inconsistent, obviously.  All good EXCEPT for the wide-mouth (180gr Gold Dot) JHPs.

The 24-lb recoil spring didn't help with those JHPs.

Full-power FMJs fed 100%.

The increased weight RSA won't necessarily help feeding issues, if it is a feed ramp / HP issue.

Yes, this is what I was thinking.  I'm familiar with JHP feeding issues from other semi-auto handguns.  The wide-mouth JHPs like some of the Gold Dots are particularly susceptible to causing feeding issues.

And don't worry that I'm thinking your recommendation on the 24-lb spring was bad in any way.

I am slow to jump to conclusions or freak out when I have a bit of trouble with a new gun.  Everything has a logical explanation. Eventually I, or Glock, or someone else will figure out how to get these Gen 4's (actually I'm only concerned about my Gen 4 but I'll share all I learn with other owners) to function with a wider range of power and bullet types.  Not worried about it, just sharing and gathering data.

[chucky2]

Cool was just wondering what you were saying, makes sense now.  The strong non-HP rounds, which ones were they?  PBR?  Underwood?

[GunBugBit]

They were Underwood, this product:

http://www.underwoodammo.com/10mm-auto-180-grain-full-metal-jacket-box-of-50/

[4949shooter]

I have tried a small amount of Gold dots in my two G20's....Nugent and some HSM. I haven't had a problem, but every gun is different.

If you want some more of my unsolicited 2 cents, the Hornady XTP's have been feeding excellent in both my Glocks. I have fired 155 grain and 180 grain both from Hornady original ammo, and 155 grain and 200 grain XTP from Underwood.

Your Gen 4 should feed Gold dots though. I wonder if it is maybe a mag issue, where the follower isn't putting the bullet at the right angle to feed the Gold dot?

[GunBugBit]

4949, I know that the XTP bullets are shaped differently from the Gold Dot bullets.  The XTPs are shaped more like the FMJ bullets in the HPR ammo -- more conical -- and the HPR FMJs feed 100% in the Gen 4 I have.

Based on my experience with 1911s, Gold Dots not feeding is no big surprise; for example, 200gr .45 ACP Gold Dots would hang up in my Springfield Mil Spec 1911 when all other hollow points and FMJs fed perfectly.  Also, there could be an overall length (OAL) issue with the Underwood 180gr 10mm Gold Dot rounds.

Naturally I'd love it if this Gen 4 G20 fed everything I have fed it, but I live in the real world and know that I might not find a remedy any time soon.  Until I do, I'll test more ammo and stick with the rounds that do feed 100%.

For sure I'll be trying the Underwood XTP rounds.  And I wouldn't be surprised if the Nosler JHPs feed very reliably.

[GunBugBit]

Just ordered some Underwood 150gr Nosler JHP and 180gr XTP JHP.  I'll report back on how these feed, using both the stock RSA and the Glockmeister 24-lb steel RSA.

Noticed the chrono/energy data on that 150gr Nosler load -- WOW.

[4949shooter]

Looking forward to a report, Gunbug!

[GunBugBit]

I still don't have my latest order of Underwood ammo but I went ahead and shot the following, last range session:

• 20 Hornady 180gr XTPs - No failures
• 50 HPR 180gr TMJ - No failures (also zero failures with prior boxes of this stuff)
• 50 Underwood 180gr Gold Dots - loaded only 10 rounds per mag but still had a couple of FTFs
• 50 HSM 200gr FMJs - was surprised to have one FTF
• 50 HPR 200gr XTPs - 3 FTFs
• 50 HPR 180gr XTPs - one occurrence of last round not feeding

My issues are similar to those I read from many other Gen 4 G20 owners.

I suspect there is a certain energy level, based on powder load and bullet weight, past which the springs don't ideally sing together.  With the stronger loads, the slide might be returning too fast, before the rounds have a chance to rise to the proper level in the magazines, or maybe there is some frame flex, and/or maybe I'm holding the gun too tight (I guarantee I don't limp-wrist); this might not be made any better with an extra-power RSA because while the slide's rearward motion would be slower than with the stock RSA, the return motion would be faster.

I expect I'll have similar issues with the strongly loaded Underwood 150gr Nosler JHP and 180gr XTP JHP.

I would not be surprised if Underwood's milder Delta Elite 180gr JHP rounds work fine in this gun.

I'm prepared to explore more expensive/exotic RSA alternatives, and/or try stiffer magazine springs.

If no success after exploring alternatives, I'll return to all-factory components and stick with the medium-to-full-not-nuclear-power 10mm loads, such as the Hornady 180gr XTP.

I really like the gun and am happy about my improving accuracy with it.

[chucky2]

That is a bummer man, I was hoping you'd be in the 4949shooter camp at the worst, where the stock Gen4 G20 has FTF issues but is correctable with a non-stock RSA.

Chalk another Gen4 G20 up with FTF issues with stronger within SAAMI spec ammo, when will Glock do something about it...?

[redbaron007]

I still don't have my latest order of Underwood ammo but I went ahead and shot the following, last range session:

• 20 Hornady 180gr XTPs - No failures
• 50 HPR 180gr TMJ - No failures (also zero failures with prior boxes of this stuff)
• 50 Underwood 180gr Gold Dots - loaded only 10 rounds per mag but still had a couple of FTFs
• 50 HSM 200gr FMJs - was surprised to have one FTF
• 50 HPR 200gr XTPs - 3 FTFs
• 50 HPR 180gr XTPs - one occurrence of last round not feeding

My issues are similar to those I read from many other Gen 4 G20 owners.

I suspect there is a certain energy level, based on powder load and bullet weight, past which the springs don't ideally sing together.  With the stronger loads, the slide might be returning too fast, before the rounds have a chance to rise to the proper level in the magazines, or maybe there is some frame flex, and/or maybe I'm holding the gun too tight (I guarantee I don't limp-wrist); this might not be made any better with an extra-power RSA because while the slide's rearward motion would be slower than with the stock RSA, the return motion would be faster.

I expect I'll have similar issues with the strongly loaded Underwood 150gr Nosler JHP and 180gr XTP JHP.

I would not be surprised if Underwood's milder Delta Elite 180gr JHP rounds work fine in this gun.

I'm prepared to explore more expensive/exotic RSA alternatives, and/or try stiffer magazine springs.

If no success after exploring alternatives, I'll return to all-factory components and stick with the medium-to-full-not-nuclear-power 10mm loads, such as the Hornady 180gr XTP.

I really like the gun and am happy about my improving accuracy with it.

You didn't say, but how many different mags were used? Consistency usually provides the direction with these issues. Since it appears to not have a consistent theme, to rule out the mags/followers, when your UA comes in, maybe just use one mag and document. At least you can rule out or confirm.

My 357sig (G32) had one mag that always gave me fits...but until I started tracking it, I had to rule out the others. I switched out the mag spring and follower, then had no issues. I bought a .40 mag because I couldn't find any 357 mags....now I have a problem with it feeding too. That is not always the case for the .40 mags substituted for 357sigs....majority of the time they work seamlessly.

Not saying that is your problem, but that is where I would start.

[4949shooter]

I still don't have my latest order of Underwood ammo but I went ahead and shot the following, last range session:

• 20 Hornady 180gr XTPs - No failures
• 50 HPR 180gr TMJ - No failures (also zero failures with prior boxes of this stuff)
• 50 Underwood 180gr Gold Dots - loaded only 10 rounds per mag but still had a couple of FTFs
• 50 HSM 200gr FMJs - was surprised to have one FTF
• 50 HPR 200gr XTPs - 3 FTFs
• 50 HPR 180gr XTPs - one occurrence of last round not feeding

My issues are similar to those I read from many other Gen 4 G20 owners.

I suspect there is a certain energy level, based on powder load and bullet weight, past which the springs don't ideally sing together.  With the stronger loads, the slide might be returning too fast, before the rounds have a chance to rise to the proper level in the magazines, or maybe there is some frame flex, and/or maybe I'm holding the gun too tight (I guarantee I don't limp-wrist); this might not be made any better with an extra-power RSA because while the slide's rearward motion would be slower than with the stock RSA, the return motion would be faster.

I expect I'll have similar issues with the strongly loaded Underwood 150gr Nosler JHP and 180gr XTP JHP.

I would not be surprised if Underwood's milder Delta Elite 180gr JHP rounds work fine in this gun.

I'm prepared to explore more expensive/exotic RSA alternatives, and/or try stiffer magazine springs.

If no success after exploring alternatives, I'll return to all-factory components and stick with the medium-to-full-not-nuclear-power 10mm loads, such as the Hornady 180gr XTP.

I really like the gun and am happy about my improving accuracy with it.

Sorry you are still having issues with the gun. Was any of this ammo shot with the 24 pound RSA?

Just for experimental purposes, I would try the Underwood with the 24 pound spring and see what you get.

Other than that, maybe Redbaron is on to something with the mags.

I know you said you don't limpwrist (and I am sure you don't), but heavy 10mm ammo in a Glock sometimes needs a heavy wrist lock, and I mean heavier than what you would normally have your wrist at.

I would see how it works with the Underwood, 24 pound RSA, and an extra-tight wrist lock. I wish I could help you more. If you were in NJ I would suggest meeting up and allowing me and my shooting partner to shoot your gun as well.

[GunBugBit]

You didn't say, but how many different mags were used? Consistency usually provides the direction with these issues. Since it appears to not have a consistent theme, to rule out the mags/followers, when your UA comes in, maybe just use one mag and document. At least you can rule out or confirm.

The 3 factory mags.

I verified that the issues occur independent of the magazines; in other words, by process of elimination/isolation, I confirmed that no single magazine provided immunity from failures.

The 3 mags all function 100% with medium loads.

[GunBugBit]

Sorry you are still having issues with the gun. Was any of this ammo shot with the 24 pound RSA?

Just for experimental purposes, I would try the Underwood with the 24 pound spring and see what you get.

Other than that, maybe Redbaron is on to something with the mags.

I know you said you don't limpwrist (and I am sure you don't), but heavy 10mm ammo in a Glock sometimes needs a heavy wrist lock, and I mean heavier than what you would normally have your wrist at.

I would see how it works with the Underwood, 24 pound RSA, and an extra-tight wrist lock. I wish I could help you more. If you were in NJ I would suggest meeting up and allowing me and my shooting partner to shoot your gun as well.

The issues were seen with both the factory RSA and the 24-lb RSA.

I'm posting here to report on what's happening for the benefit of other G20 owners who feel all alone with their issues with nuclear 10mm loads.

I appreciate your efforts to diagnose what's happening and I'm sure I would enjoy shooting with you and your shooting buddy and observing/discussing what is happening.  The truth of the matter appears to be that the G20s, and this is even according to Glock, aren't set up to handle the stronger 10mm loads.  Some have perfect luck with all loads, but many do not.

Consider the report of one G20 shooter whose malfunctions with nuclear 10mm loads disappeared when he switched to one-handed shooting.  That's interesting and might suggest that holding the gun very firmly is contributing to the issues.  I'm only willing to relax my hands so much but maybe I'll try dialing down my grip with some of the next batch of hot Underwood I received last night.

Look at what we're asking the G20 to do -- it's something we don't ask of any other semi-auto pistol that I know of.  We are asking for perfect function across a very wide power range of loads, much more than we see with .45 ACP, 9mm, .40 S&W, etc.

I'll bet that if I shot my 1911s with loads that sizzle 200-300 fps faster than most .45 ACP, I might see similar issues.

Anyway, I don't think we should rush to judgment against Glock.  My pistol will probably function perfectly with a wide variety of quality ammo, just not the really hot stuff.  I'm not surprised because I read and heard about it before I bought the gun.  I'll take my time exploring the available options for handling the nuke stuff and of course will report on any "magic formula" I might come upon (DPM or Sprinco RSA, stronger mag springs, etc.).

[redbaron007]

Earlier in this thread, you indicate the full power FMJs loads, i.e. Underwood, were 100% reliable; however, something has changed if you are now having feeding/ejection issues. Underwood is pretty close, if not right there, to being nuclear since they teeter-totter right there at there max SAAMI specs.

Yes, I was inconsistent, obviously.  All good EXCEPT for the wide-mouth (180gr Gold Dot) JHPs.

The 24-lb recoil spring didn't help with those JHPs.

Full-power FMJs fed 100%.

What has changed?

[GunBugBit]

Earlier in this thread, you indicate the full power FMJs loads, i.e. Underwood, were 100% reliable; however, something has changed if you are now having feeding/ejection issues. Underwood is pretty close, if not right there, to being nuclear since they teeter-totter right there at there max SAAMI specs.

Yes, I was inconsistent, obviously.  All good EXCEPT for the wide-mouth (180gr Gold Dot) JHPs.

The 24-lb recoil spring didn't help with those JHPs.

Full-power FMJs fed 100%.

What has changed?

Some of the ammo that worked 100% in one shooting session was involved in failures in later shooting sessions, with the same RSA and all else being the same.

I had better luck with Underwood 180gr FMJ than with the Gold Dots.  The FMJs were all good first time out; had some left over for subsequent shooting sessions and observed two failures if I recall correctly (can't find notes on this ammo type on my iPhone, usually keep good records of this stuff but I've been shooting a lot of different times of ammo lately, not just 10mm).

I clearly remember trying both the factory RSA and the Glockmeister 24-lb RSA with the Underwood Gold Dots, not for just one session but for another.  The malfunctions occurred with both RSAs.

I see from the 10mm table that the Underwood loads are at the high end of full power, teeter-tottering at the low end of nuclear.  I would like to be able to depend on these loads as they seem of very good quality.  The gun does feed them about 90% of the time so maybe just the occasional high-end variance in energy "beats the springs".