On the Glock 21

[Slater]

We were discussing .45 caliber handguns at work the other day, and an associate of mine described the Glock 21 as being "overbuilt" for the .45 cartridge since it was derived from the 10mm Glock 20.

I've heard a lot of adjectives used to describe the G-21 (mostly unflattering), but "overbuilt" isn't usually one of them. Any accuracy to that claim?

[citizensoldier16]

Not sure what your friend means...

Is a Mercedes "overbuilt" for US highways since it was built for the Autobahn?

[txfireguy2003]

Actually I was under the impression that it was just the opposite. Since it is based on the 10mm platform, but with a larger bore, there is less metal surrounding the chamber/bore. Same goes for the .40 cal as it's based on the 9mm but bored out larger. So I was under the impression that the .45ACP version was just a 10mm with thinner barrel/chamber walls, therefore inherently weaker. But that's just what I read, I'm by no means an expert.

[loupav]

Actually I was under the impression that it was just the opposite. Since it is based on the 10mm platform, but with a larger bore, there is less metal surrounding the chamber/bore. Same goes for the .40 cal as it's based on the 9mm but bored out larger. So I was under the impression that the .45ACP version was just a 10mm with thinner barrel/chamber walls, therefore inherently weaker. But that's just what I read, I'm by no means an expert.

Yes the G21 was based off the G20. But the 45 is a much lower pressure cartridge than the 10mm.

[JonInWA]

While the G21 platform was originally derived from the G20 10mm, the interior of the G21's slide has an ounce or so of metal removed/milled out, so that the slide velocity/recoil spring parameters synchronize with the .45 ACP cartridge's performance parameters. So, in that sense, the G21 is a G20 "Lite."

Realistically, the G21 is an excellent platform for the .45 ACP cartridge. The lower pressure of the .45 ACP compared to the 10mm should at least hypothetically lead to greater longevity for the G21, all other factors being equal, but I haven't heard of longevity issues with either platform (although I don't personally know of anyone firing their G20 with an extensive and protracted diet of full-power 10mm ammunition-that would be a fairly expensive proposition...).

Best, Jon

[Detmongo]

i conduct training for a team out of PA. that uses the g21's. their weapons are about ten years old they are all 2nd.gen 21's any how every gun in the teams inventory has inexcess of 100,000 rds some guns have more than that. this was confirmed by the team gunsmith as he has all the records on the guns as far as rounds fired and repairs. according to them they have never had any major issues with these weapons as they are pretty strict on main. and parts replacemnet as needed. just saying.