Last year my hunting buddy bought 10 2 1/2" 16 Ga. hulls from RMC and we loaded up some excellent loads for Huns, mountain grouse, and pheasant, all the loads were low pressure using modern progressive powder and 209 primers. I have never loaded black powder and if I were to, I would use Mag Tech brass hulls. Mag Tech hulls are inexpensive and designed for black powder. Mag Tech brass hulls are and not suitable for modern powders, use large pistol primers and the internal dimensions preclude the use of 1-piece wads.
