Quote Originally Posted by T 20 View Post
That's about as far as I'm going to get today while I stare at the piston and think about the job, but I have a good idea which way this is going to go --- new piston.
Well after looking at the Mercury piston for a while, measuring a few dimensions and calculating some weights I've decided that I'm definitely going to have to make a new piston --- again.

There's some very weird designing went into the Mercury and Airsporter pistons which doesn't make much sense.
The distance from the front of the piston cocking lever slot to the front of the piston head is 37mm --- on a HW95 this measurement is 17mm, the weight of this 37mm of piston head is about 90grams and would be difficult to shed any significant weight from.
So it looks like it would be quicker and easier for me to machine a completely new lightweight piston body to screw the original BSA latch rod into rather than try to lighten the original Mercury piston.



All the best Mick