Hi Robert.

At a shade under 12fpe it was tooth-jarring

I dropped the power simply by shortening the spring slightly. I also sized the seal for a sliding fit - that is, the piston and seal would slide gently down the cylinder under its own weight, stopping if the transfer port was blocked.

Darren - I fitted it in a Sono Kembang GinB stock which added nicely to the weight.

However, one of my 97Ks sat in a brute of a walnut stock that I added around 5lbs of lead to - and you couldn't tell unless you tried to lift it . The simplest way was to fill a few lengths of 15mm copper water pipe with lead, drill a series of 15mm holes into the end of the stock under the butt pad, then slide the weighted pipes into place.

Paul.