NO NO NO-- DON'T FIRE THESE ROUNDS!!!!

A large rifle primer has WAY more priming compound than a pistol primer, and it is of much higher brisance (without getting too technical, just say it burns much hotter and longer) in order to set off heavily retardant coated, slower burning powders used in rifle cartridges.

Pull the bullets and save the powder. Then reload the cases with a minimum load of a quick to medium powder for a LOW -POWERED practice load. Or you can fire the primers w/o powder and start over.