Not sure what forum so this might be a place to start. Years ago P.O. Ackley built a rifle that fired a .17 lead ball with a large rifle primer. He said it was powerful enough to kill a large dog. Now I see Cabelas has one that fires a 209 primer. Kind of pricey compared to a good air gun. I thought about trying a .17 HMR in NEF centerfire action and boring out the rimfire to accept the 209 primer. Thought about having a brass inset made with a larger rifle primer pocket?
Probably never do it but sounds inteesting. When weather breaks going to do some serious grouping using CCI CB & Remington CB.
Jerry