Glock 21 MOS Gen 5 FTF issues

bdb

bdb

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So, I picked up a Gen 5 G21 MOS in late January. I am having failure to feed issues with it and not having the slide lock open on an empty mag. I thought it was my reloads as they are fairly light. I tested with Winchester white box and Blazer factory loads and while better I am still getting some failures. The empty case sometimes gets stuck in the slide or the next round doesn't fully load. It is definitely more pronounced with my reloads. None of my other Glocks (all 9mm) ever fail on my reloads or factory ammo, they run anything I feed them without any failure....ever.

What about replacing the slide spring with a slightly lighter spring? Are they even available? Finding Gen5 G21 parts is not particularly easy. Any other thoughts? Sure, I can run factory or load up some full power reloads but I never have any issues with my 1911's (Ruger and Colt) so I am little surprised the G21 won't run reliably. A friend of mine is having the same issue with his Gen3 G21 with his factory rounds. We swapped mags and ammo back and forth at the range and never found a combo that ran reliably. Anyway, thought I would check here to see if anyone has had similar results.
 
I have never had a problem with my gen 3 G21 with any ammo. You can down spring. I am sure Brownell's has springs.
 
Standard 230gr RN for factory rounds and 230gr Xtreme RN in my reloads. Possibly Berry 230gr RN depending which ammo can I grabbed from when loading mags.
 
I have the same issue with my G21 gen 5. Had trouble cycling American Eagle when I first purchased. First Glock I own and it’s the gun I trust the least. Recoil spring seems too heavy but as mentioned, gen 5 45 acp aftermarket is not great. I made some hotter reloads and it cycles great.
 
Have never ever had a problem with either my 21SF or my 21 Gen 4. Have flawlessly cycled American Eagle, Lawman, Winchester and CorBon, all 230 grain. Rather than experimenting with non-OEM RSA's, I would send the pistol back to Glock for troubleshooting. My experience with Glock Customer Service has been excellent.
 
I would first call Glock, because if it,s something that is wrong with the pistol they could fix it for nothing.
 
Wickedcoolname said:
Everybody gets insulted at the suggestion, but is it possible that you're limp-wristing it?
Click to expand...

This 100%. If it's your first Glock or you're an inexperienced semi-auto pistol shooter, you're probably limp wristing. Lock your damn wrist and grip the damn gun.

Watched my 17yo son do this every time he shot my Glocks. No issue shooting my revolver.
 
Agree that can be a cause for the issue, however, I don't believe that to be the case for me. If it was a couple times, sure, but it's much too frequent with the G21 and I have other firearms in .45 auto that I don't have any issues with ammo and/or holding a firm grip. Limp-wrist was suggested in conversations with others and I actually did test cases where I held the damn thing solid and it still happened. I neglect the gun now as I feel like I'm wasting ammo trying to prove the thing is reliable. It was much worse in the first 100 rounds than it is now ~400 rounds.
 
If you're not nursing the gun and actually gripping it right, it probably actually is broken and needs to go back to the factory for repair.

That said I would never change recoil springs, there's no need to do this normally, As in, like ever. Leave that shit to the gamers and so on. Even with the mouse farts you are making as long as they're above like 730 fps for 230 grainers the gun should run them just fine.
 
In a gen 4 glock if the spring for the slide release isn't in the right place it can do weird stuff. Not sure about the gen 5
 
Wickedcoolname said:
Everybody gets insulted at the suggestion, but is it possible that you're limp-wristing it?
Click to expand...
mav said:
This 100%. If it's your first Glock or you're an inexperienced semi-auto pistol shooter, you're probably limp wristing. Lock your damn wrist and grip the damn gun.

Watched my 17yo son do this every time he shot my Glocks. No issue shooting my revolver.
Click to expand...

Everything is possible I suppose but I doubt it. Not a problem with any other pistols, 9's or .45's even with higher power SD ammo. I have put well over 10K rounds of reloads through my G17, G19, G43 but this is my first .45 in a Glock. I know have over 8K .45 reloads completed and have about 1500 left. All were shot out of 1911's prior to the G21. My daughter had similar failures on my G17 when she was 14 but I know for sure that was limp wristing, I did fire a few mags with extra effort put into a solid grip as I know that was a possible issue but it had no affect.

Interestingly as I search for into this issue seems very common. At least there are plenty of threads on other boards about it. Seems to be most prominent in the first 500 rounds and also mostly with reloads that may be a touch below factory ammo power levels. A lot of people say they are sprung too heavy but the springs settle in after 500 or so rounds and the situation improves. I'll put the next 500+ rounds of factory ammo thrugh it before checking it again with my reloads.

My so called "powder puff" loads are 230gr Xtreme RN, 5.3gr W231/HP38, OAL 1.260. They don't really feel any lighter than Blazer or WWB but according to the reloading manuals they are lighter. I shoot 5.0, 5.2 and 5.3gr of W231 regularly through my 1911's as that is what I last loaded up.
 
bdb said:
Everything is possible I suppose but I doubt it. Not a problem with any other pistols, 9's or .45's even with higher power SD ammo. I have put well over 10K rounds of reloads through my G17, G19, G43 but this is my first .45 in a Glock. I know have over 8K .45 reloads completed and have about 1500 left. All were shot out of 1911's prior to the G21. My daughter had similar failures on my G17 when she was 14 but I know for sure that was limp wristing, I did fire a few mags with extra effort put into a solid grip as I know that was a possible issue but it had no affect.

Interestingly as I search for into this issue seems very common. At least there are plenty of threads on other boards about it. Seems to be most prominent in the first 500 rounds and also mostly with reloads that may be a touch below factory ammo power levels. A lot of people say they are sprung too heavy but the springs settle in after 500 or so rounds and the situation improves. I'll put the next 500+ rounds of factory ammo thrugh it before checking it again with my reloads.

My so called "powder puff" loads are 230gr Xtreme RN, 5.3gr W231/HP38, OAL 1.260. They don't really feel any lighter than Blazer or WWB but according to the reloading manuals they are lighter. I shoot 5.0, 5.2 and 5.3gr of W231 regularly through my 1911's as that is what I last loaded up.
Click to expand...

The two things that stand out: your experience with 9mm Glocks vs. 45ACP Glock and your experience with 45ACP in 1911's. 9mm shoots with less recoil than 45. Your 45's are all metal. Might need to adjust the grip a bit to compensate for a polymer 45 Glock vs. the 9mms and 1911's. I have a Sig 220 and an HK45C, and there was an adjustment when moving to the HK, which is polymer, for me.

The other thing that stands out is your reloads are below the factory power levels and it's a new gun, so yeah, maybe it needs a bit of a break in. I'm speculating as I don't reload and don't have these issues with my Glocks (all 9mm). Do you have the same FTF's with factory ammo?
 
Yes, I am getting failures with Blazer and WWB (in the initial post). A buddy that was with me tried mine as well as his Gen3 21 and he also had the same issues with my gun and his. He was going to the range to troubleshoot his issues with his G21.3 that he just put a new Glock OEM recoil spring into it to see if it solves his issues as his gun was used and he didn't know if it was OEM or some aftermarket spring the owner before him put in.
 
I put 200 rounds of Blazer factory ammo through it this AM. I had 1 failure to eject but overall ran fine. 2 of my 3 OEM mags will not lock the slide open on last shot. 1 of the 3 locks open every time. Ugh. Still need to put a few hundred more through it to break it in and see if it starts eating my reloads more consistency.
 
What are you planning to do with the gun?
If it’s a range toy or competition gun, then get a Carver recoil rod and lighten the springs to work with your reloads.
If it’s a home defense or SHTF gun, then put another few hundred rounds of factory ammo through it until it works.
 
Sounds like limp wristing, could be a dirty gun or ejector out of spec, bent rails, cracked frame. Does the action cycle smoothly?
 
bdb said:
So, I picked up a Gen 5 G21 MOS in late January. I am having failure to feed issues with it and not having the slide lock open on an empty mag. I thought it was my reloads as they are fairly light. I tested with Winchester white box and Blazer factory loads and while better I am still getting some failures. The empty case sometimes gets stuck in the slide or the next round doesn't fully load. It is definitely more pronounced with my reloads. None of my other Glocks (all 9mm) ever fail on my reloads or factory ammo, they run anything I feed them without any failure....ever.

What about replacing the slide spring with a slightly lighter spring? Are they even available? Finding Gen5 G21 parts is not particularly easy. Any other thoughts? Sure, I can run factory or load up some full power reloads but I never have any issues with my 1911's (Ruger and Colt) so I am little surprised the G21 won't run reliably. A friend of mine is having the same issue with his Gen3 G21 with his factory rounds. We swapped mags and ammo back and forth at the range and never found a combo that ran reliably. Anyway, thought I would check here to see if anyone has had similar results.
Click to expand...
take it all apart, wipe clean.
follow this then:
americanhandgunner.com

Lubing Your GLOCK in … 3, 2, 1 Easy Steps - American Handgunner

Since GLOCKs are arguably the most popular striker-fired, polymer-framed pistol used by law enforcement and private citizen alike,
americanhandgunner.com americanhandgunner.com

on a brand new gun until this ledge below will start looking like that - with some paint/metal taken off where shown - it may be a bit stubborn to cycle.
make sure it is wet when you shoot it.

1712434726471.png
 
paul73 said:
take it all apart, wipe clean.
follow this then:
americanhandgunner.com

Lubing Your GLOCK in … 3, 2, 1 Easy Steps - American Handgunner

Since GLOCKs are arguably the most popular striker-fired, polymer-framed pistol used by law enforcement and private citizen alike,
americanhandgunner.com americanhandgunner.com

on a brand new gun until this ledge below will start looking like that - with some paint/metal taken off where shown - it may be a bit stubborn to cycle.
make sure it is wet when you shoot it.

View attachment 869972
Click to expand...
Wet???
I’ve been running mine dry for years. Dry, and dirty. It ain’t a 1911, it’s a Glock. They run just fine dry, or with an insanely tiny amount of lubrication.

Editing this, cuz I just looked at the article you posted, which I should have done before I jumped all over your “wet” comment…

[eating crow now]…
That article is accurate, but I use a bit less oil and do it much, much less often. But, with a new Glock, I can see lubing it a bit more often during its first bunch of range trips..

Carry on.
 
Last edited:

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