Was shooting 460SW Mag warmup rounds in my fairly new 460V and had 2 minor lock ups. Load was a 230gr JHP over 29.0gr Blue Dot, a decently accurate round in this handgun. Shot the 1st round and could not cock the hammer, but didn't try to force it; instead I opened the cylinder which took a stout rap and inspected the ammo. No issues, no sticky case, no bullet jump, no proud primers. So I tried again, and had the same thing happen on round #3...couldn't cock hammer, stout rap to open cylinder. Again, no ammo issues. Switched over to heavier and hotter loads and had no more lock ups for 50 rounds. Then went back to the warmup loads, 2 cylinders worth, with no issues. Can anyone explain my initial lock ups? Anything I need to look for on my revolver that might require attention?