Originally Posted by
Frederick303
Also you can date the barrel if you can locate the BSA proof date mark. That would be small crossed swords with a letter above the handles of the swords if pre WWII. The dates stated at A which correlates to July 1921 to June 1922, C correlates to 1923/24, etc. I think I or J might have been left out.
Post war the crossed swords will have a letter combination on either side of the crossed swords like (BB -1951), BC -1952, etc. London will have no such date mark though.