Whats a good tune for an HW85k ?

[Shed tuner]

I've never owned the early '85, John, but were they 25mm?

You will know better, as you will have, no doubt, owned / worked on these, but if it's not a silly long stroke maybe best left with the standard dimensions?

My main concern would be over the cutaway at the top of the rear of the piston to create clearance for the scope ramp. My guess would be that, at the very least, a tune should ensure that there are no sharp edges left in this area and an application of high content moly paste to protect against any potential wear.

I think the V-Mach kit includes a replacement (exchange?) piston with a synthetic band at the rear?

26mm mate.. well, mine is Same stroke as the 95 - so benfits in the same way. Remember this thread ?
http://www.airgunbbs.com/showthread....-on-an-HW85-95

You are right the cutaway piston isn't a great design feature, but the screw in end block is so much nicer than the silly square pop-out tiles of the latter variants....

[TonyL]

26mm mate.. well, mine is Same stroke as the 95 - so benfits in the same way. Remember this thread ?
http://www.airgunbbs.com/showthread....-on-an-HW85-95

You are right the cutaway piston isn't a great design feature, but the screw in end block is so much nicer than the silly square pop-out tiles of the latter variants....

I hadn't remembered it, JB.

But I do now!