A good adj. reamer will cost around $130. Don't buy the cheap ones- they leave gouges and don't cut worth a damn. A couple of us have opened up 15 to 20 SxSs from the muzzle with no problem . I own an inside dial caliper so we know where we're starting and what's being removed. A friend had a Darne, and it had " jug chokes " in it. Don't know if that's common or not for them. I'll be getting a Remington 1894 Trap gun that has only I/C choke in the right barrel. Gonna jug choke that side and try to bring it back to Mod. choke. Paul