greener4me, you refer to the marking of 'NOT FOR BALL' as being relevant to this 1872 gun but in fact the NFB mark came in 1875 and were in use until 1887 so the original marks would not have this mark.
Also, it is little known that the word 'Choke' was introduced at the same time for recess or jug chokes guns. These show an identical muzzle and breech (9") measurement followed by 'CHOKE' not NFB. So the proof marks might read
M 12
B 12 CHOKE
for recess chokes
M 14
B 12 NOT FOR BALL
for normal chokes.

Last edited by Toby Barclay; 07/10/20 02:41 PM.