Quote Originally Posted by trajectory View Post
Piston ring removal, Hopefully someone better qualified than me will be along to give some advice. In the meantime I think there might be something on YouTube, hopefully, have a look for servicing a Webley senior or mk11 Service air rifle as they have phosphor bronze rings. Only thing is if they are servicing them they may not remove them for re use or they might already be broken. They are brittle so in motor engineering you used to push a ring from one side & wiggle a thin shim in the gap that appears opposite, then you move around 120 degrees & repeat, then another 120 degrees till you have three shims in place holding the ring open. Then wiggle the three around till they are at 90 degree spacings, then insert a fourth one. The shims are small in width & very thin but strong enough to hold the ring open , just enough to slide off the piston. Well that's one way old cars were stripped down. Same might work for your BSA but wait till someone else gives you another idea. Maybe thin but strong plastic might be enough, cut from packing material?

BUT they are BRITTLE so research it well, & choose whichever method you think is best for you. Once broken its too late to go back. It's your decision.
The above is bang on advice, all depends on the grade / type of bronze used (Oilite thro PB2 or 660 if you are lucky etc.) as some are more forgiving, I use both the shim method and also the spring the ends with thumnails gently until clear.....both can be risky!

ATB, ED