Yes it was a .45 1911, I didn't mention the caliber as I sort of consider the only real 1911s are the ones in .45. I decided to shoot a box of .45ACP and the only choice I could make of the Ranges hire guns was a 1911.
I suspect there is more energy in one round of .45ACP then a 12g capsule of Co2 I just didn't want people to think that shooting a blowback is just like shooting the real thing