I had the feed pawls on a GPMG fall to bits once. And the firing pin on a SMG wore down to the point where it didn't always fire the round - that took a bit of working out as the percussion cap was indented. Blame was being placed on the ammo until it was realised that only one weapon wasn't performing. But no problems ever with the SLR. These were weapons that would have been 18 years old when I started using them and 33 years old when we stopped using them. (Obviously, we had tea breaks in between).I got to fire an shit-ton of ammunition through the SLR, SMG and (mostly) the GPMG. I admit I have a crap memory, but I can't recall anything ever breaking on any of those in normal use; abuse and accidents are excluded.