I called last week about having 2 - 26" stainless .50 cal barrels fitted, for my sons. It didn't seem to be a problem then. I ended up buying a new stainless Huntsman and a good used spare barrel elsewhere so I didn't send any frames in. To me, the best way to go is to buy a rifle you like with a SB2 receiver and add the .50 barrel as an accessory. I get the sinking feeling that we probably shouldn't wait too long on ordering any accessory barrel, but that's just me... I'm not worried about primer holders, I expect to make breechplugs to handle 25ACP, Hornet or .32 S&W, haven't decided which yet.