Can a chamber reamer that has been used too often or damaged in any way be detrimental to the accuracy of a rifle?

If the throat portion is dull or damaged it will certainly be detrimental. Regards, Bill

+1 Bill Leeper

Only the portion of the reamer that touches the lands and grooves will have an impact. The chamber body and neck is simply a containment vessel for the cartridge case. I once had a chip snag in the oil groove of a solid pilot that made quite a confumblement. I had to set the barrel back a couple of turns to clean it up. I have since taken to pushing oil trough the barrel and I don't buy reamers with solid pilots and oil grooves ground in them. I also had a barrel once with a tight spot in it. The removable pilot got stuck in the tight spot. It didn't do any damage to the barrel but the reamer cut 75% of the pilot away before I pulled the reamer to clear chips and noticed it. I suspect a solid pilot reamer would have done a lot of damage before one figured out what the hell was going on.