Air gun tuning kit
Air Rifle Tuning Kits

HW45 finally tamed!

A worlds first?

After completing all the orders before my 3pm post run, I found myself with a few spare hours to play!

I love my HW45. Its big, clumsy, heavy and not particularly accurate, but there’s something about using it that just makes me smile.

I decided to see if I could improve the tuning kit I’d been working on. The main problem is the rear moving piston with a steel spring guide in the piston itself. This design actively encourages recoil, and the added mass of the spring guide adds to the woes. An age old answer to this has been to have the guide at the front (back) instead of in the piston. This is sort of ok, but not ideal and it saps power.

I wanted to employ the same basic idea behind my rifle kits. Support the spring as much as possible while allowing it to do its thing. Today’s breakthrough was a 50/50 spring guide, two identical guides half the length of the steel original and only a fraction of the weight. Add to that slip washers for the ends and the result is a very fast, and surprisingly quiet firing cycle with a greatly reduced recoil felt in the hand. I was pleased to see the power had risen from 4.5 to 5.2fpe with hobbys, while dieseling has all but disappeared after lubing the insides with the merest hint of moly.