Oddly enough, the easiest centerfire handgun ammunition to locate these days was the rarest 8 months ago. I read of a guy who successfully fired some 2000 rounds of .45 GAP ammunition in his Glock 21 (.45 ACP) pistol. The pressure on Std. .45 ACP is a nominal 21,000 CUP. It's 23,000 (equivalent to the .45 ACP +P) on the .45 GAP round. Has anyone fired .45 GAP ammo loaded in moon clips through a S&W Model 22, 25 or 625? Is there any safety reason not to.