doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Early English 20 gauge rim diameter

Fellows, Anyone ever had a early English 20 gauge that had an undersize rim cut (0.010)& 2.5" chambers and modern 2.5"shells will not seat totally in the chamber without forcing them? I have a Churchill circa 1910 that seems to have this problem and I am not sure what to do or who to send it to. Any thoughts? Thanks, Sandlapper

One thought

OK, one question, might perhaps you have a 2" 20 gauge gun?
Have you tried trimming down a hull and seeing if you still have a seating issue?

On the other hand, perhaps the rim cut was made for all brass hulls with a thinner head thickness

Or, travesty, cut the rim to usable tolerances
http://pacifictoolandgauge.com/gauge-rim-cutters-nopix-/744-20-gauge-rim-cutter.html
And before you purchase, call pacific and check on if it will work in a 2 1/2" chamber and deepen the rim cut

Mike

Tight chambers and slightly undercut chamber rims are not that rare. I've had it in both British and German guns. I'd try multiple different brands of shells and see if they all sit too high. Perhaps one brand will work as is but if not I'd send if out to have the chamber rim recut. I use empty hulls when trying to figure out if I have a tight chamber or undercut rim. A empty hull will easily compress in a tight chamber. Then if it seats fully it's not the rim. A loaded shell won't compress in a tight chamber so it won't let the hull seat fully in the rim cut. What ever you do don't let someone cut the chambers to 2 3/4" just because it make it easier to find shells.

Thanks guys for the info; I tried three different brands of 20 gauge ammo and all measured exactlt the same rim diameter,so I think that I'll send it to Abe Chaber and let him ream the rim slightly. A couple of thousandths would probably do it. And KY Jon, you are right; I will keep the 2.5" chambers. thanks, Sandlapper

sandlapper, I had the same exact issue (undersize rim cut) with a Churchill 20 gauge SLE Premiere. Kirk Merrington adjusted the rim ever so lightly for me. Agreed that if it is 2.5 chambered leave it that way.