Tankers usually have a pistol but even that seems to be changing. My son was a tank crewman for three years, of which about 15 months in Iraq. His first photo sent home showed him with his pistol in a drop leg holster and a shotgun, of all things. I think he told me that was just for the photo (which suggests all photographic evidence is suspect). Anyway, they later turned in their pistols. Everyone carried either a carbine or rifle. All the other photos had tank guns.
While looking into .45 ACP weapons still in use by the U S military I found that the M3 Greasgun was still being used as late as 2008 at least.
There were two older armored vehicles that had weapons racks that were in spots too small to fit a rack for the M4 carbine. One rack was actually on the inside surface of the vehicle comander's hatch cover, so he could grab the Greasegun on the way out of the hatch.
I don't remember which vehicles these were, not the more recent designs apparently.
I think these Greaseguns were conversions to 9mm, but not sure about that. The original WW2 design of the Greasegun called for easy conversion to 9mm for use by allies.
A commercial grade 9mm is stocked for the converted Greasegun, the STAGNAG round is apparently too hot for reliability. They probably use the STANAG 9mm regardless.
I have no interest in owning a Glock for several reasons, but mainly because one would have to be an expert on the manufacturing history and totaly dissasemble a used or NOS Glock to determine if it has had all the factory replacement parts called for in the safety recalls of almost every model of Glock ever marketed.
If I was absolutely sure that the pistol was as good as it could be built, I'd still only use it as a lightweight for special purposes. I just can't put any faith in a plastic framed pistol for extended serious uses.
As for degraded plastic, several of the factory recalls have been due to that. Pieces of plastic breaking loose inside, and an early issue of the sand colored pistol degrading within months due to a reaction with the pigments used.
As far as I'm concerned the Glock has no resale value. I just wouldn't risk money on a used one.
The Glock is the only handgun I've heard of catching fire in a glove box.