Cheers; At the moment its in the safe, only a small job to do which is smooth out the cocking slot for a screw to ride in that keeps the piston centred; its a bit tight and gritty but other than that it shoots well.

Power vs accuracy is often a matter of pellet choice and getting used to how the rifle likes to be shot.

considering the HW77, full power is only around 15-16fpe so no magnum anyway so its not a huge difference to the uk power. Ive had the most changes in my TX200, which summarised below:

(the TX200 mkiii is really made for export / high power, so the brits are less keen on this one compared to the older mkii which was 12fpe)

- Factory standard full power - 15ish fpe; snappy cycle with a bit of thump, stacked pellets with JSB exact Heavy 10.34gr. 

- added spring guides from TBT - made rifle smoother but didnt change power or accuracy

- reduced power for target shooting with TBT short sproke extension; this uses the full power spring for a quick snappy cycle with less felt recoil, and reduced air volume which basically replicates the older mkii.  Best pellet now JSB exact Express (hates the heavies now with reduced power) and around 11fpe

- went to a skirtless piston from UK, recoil is reduced further, spring is still a strong spring so a quick cycle - very efficient. similar power to above but slightly lower, now it likes QYS Streamlined pellets which is unfortunate because they arent readily available here.. JSB Express are second in line.

so a matter of getting used to the rifle and how it shoots, how it likes to be held, and pellet testing when you change power. magnum power will be harder to control, think 22fpe HW80, Diana magnums etc, but if they have a good barrel and predictable trigger they have the potential to be just as accurate as low power if you do your part - low power is just easier to achieve the accuracy / consistency..

Thanks, but im just putting together other folks bits so cant claim any of their kudos, but its coming together nicely.

The CS stock is nice, the thumb up groove is really comfortable. They've been making stocks for a lot of the UK brands in the 80s and 90s (Theoben, Venom, Air Arms, etc), and their current offerings are still in that style which i like. 

Thanks, it looks great installed with the jeweled finish in the breech area.

Yes, it was expensive compared to some kits, about the price opf buying a cometa fusion...

But when you consider that the piston is titanium, and its the complete internals including the compression tube with breech seal, piston, piston seal, piston liner, spring, spring guides and spare washers, the finishing etc, and the labour to make it all, prelubricate it so its a 'drop in' kit, and test its power before getting out the door, im ok with the price.. oh, and a sticker too..

Its installed now ands shooting 11.2ft lb, and its nice and smooth. Not super fast - 740fps-ish, but nice to shoot.