I taped a bunch of long, 1/4" socket extensions together and turned it with a tap wrench. The adjustable hand reamer is an Uxcell brand from Jeff's Dollarama, size 13.75mm to 15.25mm. If I had it to do over, I would remove the barrel, unbreech it, and ream the tight spots from the back end rather than feed it all the way through from the muzzle.