Take a snug fitting brass bore brush and clean the chamber good, then use a good snug fitting patch to remove the residue from the chamber. It may be helpful to clean the barrel at the same time since from your text I have the impression that the rifle has not had a lot of preventative maintenance through the years.

drover

223 Rem, my favorite cartridge - you can't argue with truckloads of dead PD's and gophers.

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