I had to chop a few coils from the spring as it would, in all likelihood, have placed far too much stress on the internals as it was. Plus it was a bitch to try and get it all in.

Had a plinking / chrono session and it's doing between 10.3 and 10.5 ft/lbs and shooting nicely, which is about where I was aiming at.

It'll probably rise a bit as the internals bed in and should end up at the right balance between power and shooting sweetly. I'll keep an eye on it with the chrono.

Thanks for all your help / suggestions lads.