I ran a fair amount (400 rounds) of heavy (320 grain) 44 mag stuff through an early 629 and did run into a few problems. The recoil was brutal. Occasionally the bolt would unlatch and the cylinder would rotate. And rather frequently the ejector rod would unscrew tying up the gun. Another later gun, 629-4, I ran standard loads through didn't have any of those problems. It was more annoying than anything else. I don't think anything was stretched or anything like that, but I didn't feel like those loads were a good match for that gun.