Not sure about regulation, John, but the rifles may be designed for the shooter to regulate /zero them themselves, like the regular Pedersoli double breechloading rifles and double muzzleloaders are. I did invite them to post here with more details, so let's see what they say when they come here. In any case, for a $ 6995 retail SRP for a 450 NE rifle that is proofed for the 450 NE, the price looks fantastic. I'm betting that someone is soon going to take it after buffalo in either Australia, or Africa soon . . .