For $66 I can get a reamer to to counter bore the 96 I have that had the mud dauber's nest in it. Seems the best way to go with it. I'm not getting any more responses either here or Joustericon, so I don't think I have much to offer Criterion in the way of help. I don't know if you've ever done any hand chambering John, but it's a pain in the wrist! I'm chambering a heavy Wilson blank that I'm putting in a Kragicon receiver. This is obviously going to take awhile, then I have another, then that's the last hand chambering I'll ever do! I may finish the two by spring.