I wasn't aware and my friend wasn't either. He had a guy reloading for him. The regular magnum case on the left locked his S&W revolver up. The special is on the right and is actually headstamped Corbon 500 S&W Magnum but has an "R" which designates to use Large rifle primers. I unloaded the remaining loads he had and the bullets were 350 grain and the smaller cases had what looked like H110 in them average of 14 grains. The larger cases I unloaded , first one had 43.4 grains and the next one had 68.0 grains H110...lucky in locked up...a second one would probably took a hand or something. The case on L was actual one that locked the cylinder up...had to pay a gunsmith $45 to unlock it....he sent it back to S&W because it has a lifetime warranty on it...I'd say he'll get a new cylinder. Recipe for disaster.