Originally Posted by
Mattatack
Firing cycle sluggish at 12ftlb. I spoke to terry robb some years ago who said he'd had several come back with stripped piston seals
True on both counts, in fact some tuners short stroke these guns.
TBH lugging all that weight around for a 12 ft/lb gun does not make much sense, mine is running around 20-ish and it's great at that level, accurate as a wots-it.
Mine also lost it's seal, a new one is now glued in place, fingers crossed. It's actually not a big deal when this happens, so much so that you don't realise anything is untoward before you realise that the pellet did not reach it's target, you open the breech to reload, and find that it's still there.
Steve Pope told me that they used to mod the piston to take an HW80 seal. This is thicker and in effect reduces the stroke a tad too, unfortunately if you have a full power one it reduces the swept volume a little too.
**WANTED**: WEBLEY PATRIOT MUZZLE END; Any Diana/Original mod.50 parts, especially OPEN SIGHTS