This sounds ABSOLUTELY AWESOME, Dave.
I'm frothing at the mouth already!!
I know I'm not the first...many, many springer fans will have debated for years as to which would be the best way to go......narrow bore / longer stroke vs big bore / mega short stroke.
Much of the more recent thinking has pointed more towards the smaller bore option being the favoured option, with lighter piston weight and the fact that pellet release pressure is achieved whilst the piston is further from the cylinder end wall, supposedly giving more manageable surge characteristics.
But THIS is very encouraging. Yes, your short stroke 80 I tried last year was beautiful. Okay, we weren't doing clinical accuracy testing, but I have no reason to suppose that it would not be anything other than very accurate and forgiving.
And you say that this latest project results in an even better firing cycle. FANTASTIC!
This could finally lead to the 80 re-establishing itself as a firm favourite amongst UK shooters.
I know I asked last year if you'd consider making a short stroke piston commercially available.....If this thing works as well as it should, and judging by your findings so far, it does, this could be a very simple drop-in affair, so easy for those with only basic skills to completely transform their rifles at home; something that many couldn't undertake a reduced cylinder conversion without more tooling or expertise. And I really love the idea of the longer rod, as I've mentioned previously, so you don't get that "dead" movement on initial barrel opening.
Bring back the mighty 80. A big, solid, heavyweight of a thing. Solidly engineered to last a lifetime. Loads of weight to settle the aim and soak up the slight recoil.
With you mentioning the performance vs the 55....... Just think how sweet you could make one with an even longer rod, tiny stroke, set up to produce 6 or 7 ft.lbs!!!!
I WANT ONE!!!! Please!