I've made up a few using the surplus British 303 barrels, same barrel I am using on the 32-20 stub project. They are really a lot of fun to shoot, they are quiet with about the recoil you would expect from a 22 Mag. I think you could probably load up a nice sub-sonic round with cast bullets, I made up some sub-sonic loads for a 30 Carbine Handi using 170 gr cast. Larry