Common sense says you're right, but in the places whee I use the "factory crimp", it works real well, better loads than uncrimped. Until I started using it with 8MM, couldn't get good heavy loads. Evidently the slow powder wasn't building pressure properly before the bullet started moving. Factory crimp, problem solved.andy said:how can you crimp with no cannelure, hmm? Bound to damage the bullet at least a little bit.