Glock 21 Gen 5 Reports (Also weird jam with mine)

[SwampDweller]

I took one of my G21 Gen 5s out shooting yesterday (the one in the OP) along with a case of American Eagle 230gr FMJ to run through it (not all of it at once, mind you). I loaded the mag (fresh Gen 5 mag that had never had an issue before) to 12 rounds. On that first mag of the range session, it had the exact same weird malfunction detailed in the OP (again on the second-to-last round with the rear of the cartridge sticking down the magwell). This time I made sure to have my finger well away from the right side slide stop, and I was definitely not fatigued as it was the first mag of the day.

Not sure if it was me, I handed it off to a friend along with my AE ammo and let him shoot it for a bit while I focused on shooting my new shotgun. About 120 rounds later, it did the same thing to him. At that point I called it off as I didn't want to keep blowing through precious .45 ammo just to find out if it would keep doing it. I boxed the gun up and got out one of my low round count Gen 4 G21s to shoot instead. Shot 300 rounds through it without an issue, including using the same mag that had two stoppages in the Gen 5 shortly before. Also ran my USP 45 FS and HK45C for a couple hundred rounds each, also no issues.

At this point, that's such a weird jam to happen 3 times in less than 700 rounds with one G21 Gen 5, and also in another G21 Gen 5, I'm not thinking it's user error or a series of defective OEM magazines. It happened with Lawman and American Eagle 230gr. I have had consistently reliable function with those brands in particular for tens of thousands of rounds in other pistols, including other G21s of previous gens. It's frustrating because it's relatively infrequent and random, going sometimes hundreds of rounds before doing it again, and I can't begin to diagnose what the issue is. It's always the exact same type of stoppage, and on the 2nd to last round of a mag. It's even more frustrating because the G21 Gen 5 shoots so damn well. Not really sure what to do at this point, but no matter how you slice it, .45 is an expensive round to keep resetting round counts after stoppages to see if it can get to 1k rounds without a stoppage, only for it to keep happening.

EDIT: Regarding differences between the Gen 5 and Gen 4 G21, comparing the RSA's side by side, the Gen 5 is noticeably longer than the Gen 4's. This likely contributes to the heavier spring weight, as well as how the Gen 5 is softer shooting than the Gen 4.

[psalms144.1]

SwampDweller - If I were you, I'd definitely send that pistol back to Smyrna. Contact them and detail what you're experiencing, and they should be happy to provide a shipping label for you to get it back to them.

Sad to see this, unfortunately, while GLOCK's roll out of the Gen5 9mms was great, they have a track record of sending out new designs and letting the field find the problems with them (thinking back to the Gen4 fiasco, various issues with WMLs on earlier .40, etc).

[RevolverJIM]

While I haven't had any problems with my Gen 5 G21 I can tell that the RSA is somewhat stronger than my Gen 4 G21.

A bit puzzled why Glock would change the RSA on the Gen 5???

My guess is that the stronger RSA is not allowing the slide to go all the way back during recoil, causing the slide to catch the top of the next cartridge case body and not the base of the next cartridge in the magazine.

I have seen the very same symptoms in my Gen 5 G17 when shooting slightly under powered ammo (reloads), even though the slide is usually, but not every time, locked back when the last round is fired.

[SwampDweller]

While I haven't had any problems with my Gen 5 G21 I can tell that the RSA is somewhat stronger than my Gen 4 G21.

A bit puzzled why Glock would change the RSA on the Gen 5???

My guess is that the stronger RSA is not allowing the slide to go all the way back during recoil, causing the slide to catch the top of the next cartridge case body and not the base of the next cartridge in the magazine.

I have seen the very same symptoms in my Gen 5 G17 when shooting slightly under powered ammo (reloads), even though the slide is usually, but not every time, locked back when the last round is fired.

I really don't know why it's happening. At the end of the day what matters to me is whether I can trust them or not, and I cannot. If I were more committed, maybe I could diagnose and figure it out, but I'd rather put my time, energy, and ammo into other guns.

[JonInWA]

Again, I'll echo the recommendations to send to Smyrna, with a detailed letter describing your use protocols and the issues experienced.

This also reinforces to me why my Gen 3 G21 will be sticking with me, irrespective if I in the future get a Gen5 G21 or G30...

Best, Jon

[SwampDweller]

Again, I'll echo the recommendations to send to Smyrna, with a detailed letter describing your use protocols and the issues experienced.

This also reinforces to me why my Gen 3 G21 will be sticking with me, irrespective if I in the future get a Gen5 G21 or G30...

Best, Jon

I sold both my G21 Gen 5's yesterday and now only have my three Gen 4s, as they shoot well and I don't have any reliability issues with them. It's possible my trigger finger was interfering with the right side slide release causing the jams, but either way, they had to go.

For at least a while, I'll be sticking with my Gen 4s, and may even pick up a Gen 3 SF since spare parts are more available and the Gen 4 G21 will likely be discontinued, as with the 9mm and .40 Glock Gen 4s once the Gen 5s came online.

[JonInWA]

I did notice that the ambi OEM slide stop/release on my Gen5 G23 did seem to protrude out more so than on the previous generations-while I put on the extended one, arguably I really didn't need to on the Gen5.

But now you have money to spend on a GP100!

Best, Jon

[randyho]

In fact, thinking for the long term, I wonder if I should replace my two Gen 5 G21s with Gen 3 21SF’s. My reasoning is:
1. Glock has a track record of discontinuing Gen 4 models in calibers where the Gen 5 has come online, but continue Gen 3 production.

2. I can easily find OEM slide and frame parts kits for the Gen 3 G21SF and keep several to keep the guns going the rest of my days, whereas I can’t find any OEM slide and frame parts kits for the Gen 4 G21s.

Curious how the grip size differs between the two. Considering a switch to gen 5's but given the above, I'm not sure there's an upside.

The Gen 3 G21SF and my hand size has no reason to work as well as it does.

[JonInWA]

Curious how the grip size differs between the two. Considering a switch to gen 5's but given the above, I'm not sure there's an upside.

The Gen 3 G21SF and my hand size has no reason to work as well as it does.

Sometimes perceived ergonomics are different from actual results achieved-going with the empirically derived actual results is usually a good way to go.

Best, Jon

[SwampDweller]

Curious how the grip size differs between the two. Considering a switch to gen 5's but given the above, I'm not sure there's an upside.

The Gen 3 G21SF and my hand size has no reason to work as well as it does.

There's not enough difference in the grips for me to make a measurable difference in shooting. Subjectively, the Gen 5 felt better, but that could've been because of the Talon Grips, which I haven't put on my Gen 4s.

There's nothing wrong with the Gen 3 G21SF, and I don't think it's a bad idea go go "all in" on it as far as G21s go. They're well proven, accurate, shoot well, there are parts everywhere, and it looks like it's not going anywhere from Glocks lineup, which can't be said for the Gen 4s.