Air Arms Tony Leach O-ring conversion? Or HW 45 seal

That's a good question JP.
I'm surprised you just didn't ball up some duct tape and zip tie it on the nose of the piston! Does the TL piston have a dovetail for the seal or is it straight cut like the HW45?

Not to hijack your post, but since I recently got a TX200HC set up with a Tony Leach 22mm skirted piston, I've wondered what improvements or modifications people have done on the kits. Especially spring changes or possible piston seals substitutions.

I’m running an Aussie cup seal in my P1 in .22 cal. I did gain some velocity over the factory seal. After a bit of work on it, I have it shooting 13.4 grain JSB pellets at 460fps. The 45 and P1 do much better with a shortened spring and increase in compression chamber.

Hobbyman2007 said:

The 45 and P1 do much better with a shortened spring and increase in compression chamber.

Click to expand...

I already have the P-1, a new spring and a new Aussie Seal. How much did you shorten the spring and how do you increase the compression chamber.

Perhaps a bigger question is how is the accuracy at that power?

I took two coils off the spring and to get more compression chamber volume I took some of the material off the plug on a lathe. I don’t have my notes with me but I seem to recall 2mm. Also added a small channel in the face of the plug to direct the air into the transfer port. The pistol has a less harsh shot cycle than factory. Don’t forget to size the pistol seal. I found the Aussie seal to be a little on the big side.

O-ring type seals on spring pneumatic air guns are short lived !!

O-rings can move dynamically but can & do roll within there containment groove/channel under high speed dynamic motion. They are also bias to fret on the surface of contact if not rolling and killing the seal they might be making otherwise.
An o-ring is just not designed for that type high speed cyclic dynamic motion.