Hi All,
I am very interested in this thread, as I am currently looking at an early side lever break action single shot rifle by R Johnson of Liverpool. It measures .429 diam and has 64 stamped on the underside of the barrel near the proof marks. The chamber is 3 1/4" long. The nearest I could come up with from my books is 400 x 3 1/4 Kynoch or 400 x 3" Purdey.
Rim diam is approx .537", Base diam is approx .495, Neck diam is approx .465".
A 410 shotshell fits and a 9.3 x 74R fits.
The serial number would appear to date it quite early at between 1860 and 1870.
Rifling is 5 groove with .100" wide lands and .200" grooves.
These measurements have been taken from a sulphur chamber cast.
Any help appreciated.
Regards
LesLeeSpeed