They can be sensitive to slight variations so be very careful when loading magnum stuff. I only load them as a low velocity sub-sonic round with 3/8th. ounce of small shot for ratting or else as a blackpowder load for an older gun. I also mainnly use card and felt wads and rollcrimp. Fiddly little devils. I ddi use some plastic wads in the ratting load but had to reduce the powder load quite a way to get them right. Lagopus.....