Cheers guys, the tuning kit replaces the old steel spring guide and front top hat with custom made delrin replacements and a custom made Swedishicon steel mainspring has delrin rings added to the front and rear of the spring.

The heavy short piston gives a longer stroke and greater capacity.

The existing parts (piston carrier and receiver tube) highly polished and everything re-fitted with a special lubricant.

Lots of modern technology employed, unheard of 35 years ago when the BSA was built.