I can only think of two guns that gave me any problems, and one of them got fixed under warranty. The first was a vintage Yugoslavian Mauser rifle that I couldn't hit anything with. I think the barrel was shot out and I sold it to a gun shop. The other was a Smith & Wesson Model 624 .44 Special revolver that I bought brand new. As I was cycling the gun, I noticed that at certain parts of the cylinder it took more effort to cock the gun. I concluded that at certain points the cylinder was dragging on the forcing cone. Since the gun was still under warranty, I sent it back to Smith & Wesson for service. When it came back, I got the impression that not only did they deal with the cylinder dragging, but they also went over the whole gun and smoothed it out. I still have that gun.