Just pulled apart a BSA Mercury, early Mk2, worst strip ever, its not been apart since 1975 or whenever it was built!

First off, I struggled to unscrew the rear block. Put some heat on, then some more heat, then some internet to make sure there is no hidden pin or screw, then more heat and a big adjustable wrench and a copper face mallet.... there she goes.

Cocked the piston back with the linkage, as its sticky, the main reason for the strip, and with the rod out of the rear of the action an inch, thats it!
Finally realised that I could jack the piston out by clamping the piston rod in the vise, and using the barrel against a long piece of wood, bit by bit!

nearly 2 hours!

And how many seals does it really need? An O ring and a leather washer and a circlip? (leather washer crumbled) Is there a better solution for a replacement?


Thanks!