Do you think it was the heavy recoil spring that sheared the lower lug on your 1911 barrel? How many shots did it take? I guess that's an advantage of the Glock, in that it doesn't have a pin that the barrel rides on. It looks to me like the barrel just rides up a ramp until it locks into the slide, and the bottom lug hits the slide stop. I suppose that the polymer frame absorbs the impact a little better. Not that I've ever worn out a 1911.....