I have a BSA Mercury Mk I .22 which is shooting at 8 ft/lb.

I have dismantled the rifle and have a spring handy for HW 35/ 80 which will fit. It is rather long I feel at 32 coils and needs cutting back to suit. I have already turned up a nice spring guide to suit the Merc. and the HW spring.

How many coils should a Mercury spring have ?

Before you ask, the spring removed was non standard and way too short as I was able to remove and re-fit by hand without the spring compressor I have.

Also I have a chronograph to make sure it stays under the 12ft/lb limit

Ideally, I am looking for 11 + ft/lb and smoothness.

Thanks in advance for advice guys.

Paul.