Modify bare 209 Lehigh breech plug to fit NS primer

[hockeyref]

OK so I got all the parts to convert my night original disk to bear 209 primer with Lehigh breech plug and adapter. The problem is I have 10,000 noble sport primers that are just a little too big in diameter for the breech plug. I measured the primers and they generally measure .243” but the very end they are slightly out of round and in one direction it will measure .245”. Looking for suggestions on how to open the breech plug up maybe .001” or so to allow these primers to fit. I’m thinking of slotting an aluminum rod and wrapping it with some 600 or 800 grit wet/dry paper and hand turn. Or maybe give the end of the primer a twist or two.

 

[GM54-120]

17-22cal bore brush
Some patches
Drill to chuck up the bore brush
Polish rouge coarse grit...like a valve lapping compound Standard Series Metal Polishing Compound Bars

Wrap the patch around your brush
Apply the lapping compound

Spin to Win

Go slow and keep testing with a primer. Done this to several Lehigh plugs but just to polish the pocket with fine grit compound. I got a few hundred NSI 688 (mag) primers i need to use up so i may try it on a spare plug.