I've ordered a couple of parts.......recoil spring, hammer spring......I asked how much $ for the particular springs for the 15-22 and they asked for my address and sent me the springs. No other questions asked. Free. Gotta love S&W Customer Service! If my sub-sonic conversion works out, I'll be ordering another bolt assembly. If it works out, I'll have a quick swap to go from standard and HV ammo to subsonic with just a change of the bolt. I really don't expect to get another assembly for free. I'll gladly pay the price if I get it running though.