A while back I was out shooting with a friend who brought out his SA Omega in 10MM, a high performance pistol for a high performance cartridge. In a moment of weakness he had bought a ziploc bag of reloads at a gunshow marked 10MM 155 gr. RNFP, copper plated. First four shots didn't feel quite right so he stopped firing and went hunting for the 4 cases. Every one was a hair away from rupturing through a large bulge in the side of the web of the case. We pulled several bullets later and discovered that the loads were obviously hot from the experience at the range but the bullets were 180 grain, not 155. So a hot load for the lightest bullets found in 10 MM cases was actually throwing the heaviest bullets for the 10MM case. Pressures through the roof in an already high pressure cartridge. To make matters worse we measured several cases we pulled bullets from and they measured from .008" under trim to length to .007" over max. case length. I am sure he will never buy gun show reloads again and I would exhort everyone reading this it is not worth the risk no matter how lucky the past has been to you.