I have 5 K22s and as I was renting a 44 special reamer I had them send a finish reamer for 22lr cylinders along, because K22 are notorious for sticky extraction.

I kept the reamer well oiled and completely cleaned it after each chamber. When doing things like a 44 to a 45 chamber I clean and oil multiple times be chamber, but this was making VERY light cuts and producing very fine chips and not loading the cutter any real amount.

18-4 very little actual material removed, but, had a little resistance from start to finish. I have never had much of a problem with this gun.

17-2 a bit more than the 18, but, only started to really drag at about 1/2 way in

pre 17 4 screw. Probably had the most material removed but never did much for first 1/3

a pre 18 and a pre 17 5 screws. Not much removed and only about 1/2 the chamber had resistance. last 1/4 a bit more.

Did I have to do this, not really, I have never had one get really bad, maybe because of my ammo choices, I don't know, but I do know all my chambers are now correct and uniform. I also did an old Taurus 6 shot that's about J frame size mostly because it had some dings on the edges of a couple recesses from being dry fired. Its going to go down the road one of these days.