I am thinking of getting a can for my M4 so that if I have to use of in the house I don't do serious damage to the hearing of all occupants. Does anybody know the drill to get the stamp? Do I have to have the stamp before the can or do I have to have he can first. Do I have to get he stamp and can together from the can vendor or do I apply to BATFE or whoever separately. I appreciate any input.

