Hi,

A friend recently bought a BSA Standard Pattern.
The gun turned out not to have a piston seal
Wouter bought a new leather piston seal from Knibbs.
It didn't fit first. Without reducing the diameter, he squeezed it in really tight and turned the piston around in de cylinder with a drill.
It now fits.
The tap doesn't appear to leak.
But... power is low; 5.9 ft/lbs with 15.89 gr JSB 5.52 mm
I advised to try H&N 5.55 mm; power is even lower with this pellet.
The gun has a new spring, also from Knibbs, apparently for BSA Standard.

Please may I ask some questions on Wouter's behalf:

1. what is "normal" power for these? I thought they should do legal limit quite easily?

2. my feeling says that the piston seal isn't right. Probably too tight, even though the leather will have compressed by now.
Do these piston seals need sanding down? And is neatsfoot oil really the best oil to use? Any good alternatives?

3. any recommendations for the best spring to use?

4. any recommendations for the best pellets to use?

Many thanks, Louis