Wot size thread?
Hi From a newbie...
I have a 310 Cadet and I am making a new eyepiece for it`s #8 BSA tang sight but I cannot fathom out what the thread is, I have tried metric, BA and unf-unc sized taps of approx size but NONE fit correctly. I would love to fit the new sight using the correct BSA thread.
Any help would be appreciated.
06-22-2012 02:10 PM
Friends and Sponsors
Really Senior Member
Try asking on the Lee-enfield board, you might get more responces to your question. If not there, try britishmilitaria.yuku.com. Someone there should be able to get you an answere.
I have a PH-7A with an ajustable eye piece on my cadet.
Maybe 40 tpi?
Get hold of a thread gauge and measure the pitch. Parker-Hale sights use 40 tpi for the eyepieces. My guess is that BSA might well have used the same.
If it is indeed a 40 tpi thread, then look for a model engineering supplier. 40 tpi fittings are (were?) common on live steam models, and taps/dies are available from such suppliers.
Last edited by Patrick Chadwick; 06-29-2012 at 03:30 PM.
Originally Posted by Patrick Chadwick
If you have not got a thread gauge, see if a 4BA bolt (which has 38.5 tpi) nearly fits the pitch. If so, that increases the likelihood that it is a 40 tpi thread.