If the action is close enough to discern the threat, the bullet won't matter. The old 55gr bullet in a 12 twist barrel worked just fine. The important thing is having enough. Being a half empty sort of guy I felt a little weird just humping the required 250 rounds. I felt safer with 400 rd in magazines and 600 more in charger clips. When life became exciting I had lots of friends who didn't laugh at me anymore. LOL!