I think punk works tests showed that the hammerhead ID is .700 if IIFC I highly doubt the so called rifling even made contact. Ive had hammerheads before IMO and the opinion of several much smarter people than I. Its a waste.
PS I think the performance increase your seeing is due.to.the hammerhead being over bored all lowing the fs round to pre spin itself as it flys down the barrel. In other words you could get an overbored lapco 1 piece and save a lot of money and still accomplish
Last edited by Keebler; 08-03-2012 at 09:42 AM.