Just to be pedantic, I feel I should mention that .45 GAP is a cartridge, not a firearm. I don't believe Glock or any other firearm manufacturer sells a pistol called a "GAP." Is it safe to assume that you're really asking who has fired Glock's .45 GAP model, or are you asking about firing any make or model that's chambered for .45 GAP?
Yes, you are correct, but since the .45GAP cartridge is almost totally only used in Glock models G37, G38 and G39 (Gen 3 and hopefully someday Gen 4), the two (cartridge and handgun model) have become synonymous in common parlance. However, I apologize for any confusion I may have caused.
S&W worked with Remington to make the 40 caliber, its chambered by others (I believe glock beat them to the market actually in delivering a gun for it). Its S&Ws design but originally Remington produced.
357 Sig was designed by Sig. Again chambered by others but its a Sig cartridge design and originally produced for them them by?
the 45 GAP was designed for and or at the auspices of glock. It is chambered almost exclusively by glock. Ergo, its their ego cartridge. After all, the famous firm of glock can't not have their own cartridge because S&W does and Sig does.
Note that glock now refuses to put name "Sig" on the 357 caliber guns they chamber for though 357 Sig is the correct designation. Ditto for the 40 S&W.
the 45GAP is a glock boutique cartridge by any definition and it says 45GAP on the chambering designation.
DPA and others fire the 45 GAP in competition revolvers because of the shorter length is quicker to load. So I guess 45 GAP in 45acp is ok.
No its not. Its shorter, it does not head space correctly in a semi auto. Its a recipee for a KABOOM! A revolver uses a clip to head space it in the cylinder and no problem (like shooing 44 special in a 44 magnum).
It was purely my total ignorance that glock had come out with their boutique cartridge that led me to buy a box I thought was 45 ACP and to shoot it. Call it stupidity if you will, and possibly deserved, I will leave each to decide for themselves.