Thanks WD, great write up.

So the lesson here seems to be that (very) short strokes in large diameter cylinders do work, but need heavy pistons ?

I may revisit my sirocco that we'd spoken about previously - .177, 31mm bore, I short stroked to 61mm but only got 9 FP - maybe I should add some mass to that piston....

Anyone else looking for to the springer bash even more now ?