doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Dead give-away or not

IF memory serves me Champlin (importer) stated bores .731, to the untrained eye it appears bores were honed and polished (removing pitting?). I've spoken with James Flynn about the stock bending since he's only 1 1/2 hours drive away, I'll ask him what he thinks.

I believe I read something once about English gunmakers boring long tapers with little constriction and coining the term "improved cylinder" to describe it, as opposed to "choke" boring. Could that explain the RB configuration and lack of marking?

The choke marking was based strictly on the constriction. .008 or more, the proof house would mark it Choke.

As to improved cylinder, our British friends can confirm, but I believe that improved cylinder for them is more open than it is for us. More open than their "quarter choke", which is .010 in a 12ga, which is the traditional definition of improved cylinder on this side of the pond.

.731 bore diameter would mean the gun is out of proof if marked 13/1 and not reproofed.

Imp Cylinder traditionally was 5 thou constriction, 1/4 choke is 10 thou as L Brown said.