It took me some time to realize the real genius of Browning, which was in the timing. Even today, there are arguments about exactly what happens exactly when (the main one being does the slide move before the bullet leaves the barrel, and the answer is yes. There's nothing to prevent it). I don't think JMB did many calculations, and he sure had no computer. He just understood what had to happen and worked on it until it did. I would imagine that production drawings came out of Colt's drafting room and were reverse-engineered from a working pistol. What an incredible man was JMB, but I'd bet he would be astounded by the continuing popularity of the 1911, figuring that surely by now someone would have made a better combat pistol. Of course, we know that he did it himself, or thought he did, with the P35, but there's just nothing like a 1911.