AirGunTech: Re Engineering Spring Powered Air Rifles for smoothness, consistency, and to better suit UK power levels.

HW85 rebuild and Tune

The early HW85 (Raised scope rail model) is really a small HW80, it has a detachable trigger block like the 80 but uses a 26mm piston. Im rebuilding this one for a friend so decided as I have neglected the blog a little it was time to create a build thread for this one outlining what is being done.

The rifle is not sick or broken, its old and the bluing is faded and the owner is looking for a specialist tune on the gun so its as smooth as melted butter to shoot. What I am proposing to do here is strip and clean the parts, discard the old mainspring (its a square section Ox spring) and then machine all the parts needed for the tune. The piston will have a rear bearing and inner sleeve, the inner spring guide will be recessed into the trigger block and PTFE thrust washers will be made for the spring to rotate upon. Overall it should be quite a different animal when its finished, power will be just a nats over 11FPE with lightweight pellets to keep it legal within the UK.

This is first post in the series documenting the build, to follow I will detail the strip down and clean.

To show the original condition of the gun here are a few pics as delivered to me, the action is without a stock right now but the pics do detail the condition of the rifle etc.





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