There's plenty of scope to lighten the original piston, and you could fit a proper nylon rear guide at the same time, sized to the bore for smooth running.
Yes, 27.7 mm at rear of piston, 28mm cylinder bore I wish I had taken pictures of the piston now, it looked like a poorly applied layer of chrome plate you could actually feel the difference at the edge of the chromed area. I just polished it all smooth.
There's plenty of scope to lighten the original piston, and you could fit a proper nylon rear guide at the same time, sized to the bore for smooth running.
BSA Lightning XL SE GRT project. Webley Alecto 0.177. Relum Super Tornado rescue dog
Not yet! Been up to my eyeballs in work and sorting stuff out for a charity gig, as well as trying to get the Relum finished for my sons birthday. But work means I've got the money to get it sorted, so I'm knocking up some drawings for the machinist this week and starting on getting the bits for the 25mm conversion sorted out.
BSA Lightning XL SE GRT project. Webley Alecto 0.177. Relum Super Tornado rescue dog