Unintentionally. I'm pretty sure there's not enough mass in a normal handgun slide to slam the round home fast enough for that to work, and like pretty much all handguns of this class, Glock actions lock up before firing. I've certainly never heard of it being used for rounds with the pressure of 9 mm Parabellum. It would also be hard on the gun, and again there's less of a mass budget. And of course the Glock's frame is made out of durable plastic (which is not one of it's problems, although might cause problems upon occasion).
This is my understanding from memory: one reason .40 S&W is so popular is that it's a 10 mm diameter round, so it's easy to "bore out" a 9 mm design and in theory make it work (not an option with 11.5 mm .45 ACP). As I've been told, and this is common in handgun designs, the chamber does not entirely support the brass.
You can get away with this because the brass at the base is thick (at a point it has to be because the curve up into the base can't be supported) and this sort of gun design is generally allowed. Compare to the .38 Super, which is 1,500 PSI higher than 9 mm or .40 S&W, and about 50% more than .45 ACP. M1911's chambered for it have "fully supported chambers", the original John Moses Browning (PBUH) .45 ACP chamber isn't fully supported. Also do a search on glock fully supported barrel or chamber, there are after market ones.
However I gather that Glock cuts, or in the past cut the margin a bit fine for their .40 S&W handguns, which is not a good posture to start from for an out of battery discharge.
And then somehow, without warning or requiring lousy maintenance (or of course reloads, which cause a lot of "kabooms" that are no fault of the gun), some .40 S&Ws blew up in user's hands due to out of battery discharges. Which Glock fixed on the QT. Search Google for more details, I found out about this pretty randomly in the first place. It's consistent with many other reports of Glocks having problems and how the company dealt with them, including the NYC police as I recall.
And of course take this with a big grain of salt, I'm an anti-Glock type, due to the accidental discharge safety problems I identify above (no safety, no external hammer).
This is my understanding from memory: one reason .40 S&W is so popular is that it's a 10 mm diameter round, so it's easy to "bore out" a 9 mm design and in theory make it work (not an option with 11.5 mm .45 ACP). As I've been told, and this is common in handgun designs, the chamber does not entirely support the brass.
You can get away with this because the brass at the base is thick (at a point it has to be because the curve up into the base can't be supported) and this sort of gun design is generally allowed. Compare to the .38 Super, which is 1,500 PSI higher than 9 mm or .40 S&W, and about 50% more than .45 ACP. M1911's chambered for it have "fully supported chambers", the original John Moses Browning (PBUH) .45 ACP chamber isn't fully supported. Also do a search on glock fully supported barrel or chamber, there are after market ones.
However I gather that Glock cuts, or in the past cut the margin a bit fine for their .40 S&W handguns, which is not a good posture to start from for an out of battery discharge.
And then somehow, without warning or requiring lousy maintenance (or of course reloads, which cause a lot of "kabooms" that are no fault of the gun), some .40 S&Ws blew up in user's hands due to out of battery discharges. Which Glock fixed on the QT. Search Google for more details, I found out about this pretty randomly in the first place. It's consistent with many other reports of Glocks having problems and how the company dealt with them, including the NYC police as I recall.
And of course take this with a big grain of salt, I'm an anti-Glock type, due to the accidental discharge safety problems I identify above (no safety, no external hammer).