Went out shooting the other day with some friends, took a few random guns. I only brought my G30sf and my 10/22 because im still mostly crippled from tearing my right bicep and having surgery to re-attach it, one brought his M&P .45, a .22 and a .410, another brought his M&P 9mm, and the other brought his .44 rifle he was sighting in. Anyway, there was a brick at about 40yds me and the other .45 were shooting at, he shot a whole mag at it missing everytime, I finished loading my mag and got it first time, weak arm 1 handed, i got to flip him some crap for that. Well bragging aside, the reason for the post was this, he was loading up a magazine of some new "cheaper than usual" .45 ammo and commented on how it was shorter, I took a look and it was and had a square nose bullet. Well I took a look at the box and it turned out to be .45 GAP he was about to shoot, which I stopped him from doing. So heres the question: Did I stop a pretty serious happening? Like blow the gun up serious? I know the 2 rounds dont interchange, but how serious would this have been if he would have shot them?