ZG47
AH fanatic
- Joined
- Jan 20, 2015
- Messages
- 899
- Reaction score
- 1,140
- Location
- Wellington, New Zealand
- Member of
- NZDA
- Hunted
- New Zealand
Thank you. I have now been further educated. If you want a screw or bolt for a very old BSA air rifle you go to John Knibbs OR possibly his successor by now. Mr Knibbs bought up BSAs surplus stock of parts when they stopped making firearms, that stock including parts for very old air rifles. I suspect that pretty much all the firearm parts are long gone but if you own an antique BSA airgun, that is your source of original parts.Arms manufacturing being one of the oldest manufacturing industries, often used dimensions, thread pitches and all manner of "standards" well before the development of engineering standards in the wider community hence the need for the "Enfield Inch" and some of the weird threads encountered on Lee Enfields etc. In Europe, Paul Mauser did his design sketches in metric, and then converted to Imperial approximations because his machine tools were made in England (which explains some of the odd dimensions, Whiworth thread forms and non-standard TPI). Threads on Siamese mausers are a combination of German Mauser (psudo-whitworth) and Japanese armoury specials designed prior to the adoption of either imperial or metric measuring systems.