FWB Sledge vs Giss question?

[T 20]

I think M&G’s official figure is nineteen-point-something in .22”, less in .177”.

Given that the 48/52 comfortably hits or exceeds twenty in “export” form, it makes me wonder whether Diana with the 54 are the first maker ever known to understate an airgun’s power, or whether they’ve done something to the 54s to make them a bit less powerful because that works best with the sledge?

Similarly, I wonder about how well the sledge would work if you properly de-tuned the action to make 11.a bit. I assume that U.K. spec factory models just rely on a TP restrictor, giving an inefficient action with plenty of surplus energy to work the slidey thing. What would happen if you increased the efficiency of the action to generate sub-12 m/e (short-stroke, sleeving, etc), while decreasing its total energy? Would the slidey thing still work properly?

IIRC Bigtoe did some experiments many moons ago and found that the 54 sledge still worked with a reduced piston stroke and he also found the sledge system moved by a reduced amount.

From a power point of view, from what I can gather the early D54 T01 has a longer stroke than the later D54 so could explain the 25ftlbs I recorded from a 54 T01 --- or maybe it was a made on a Monday morning gun.



All the best Mick

[DrGunn]

IIRC Bigtoe did some experiments many moons ago and found that the 54 sledge still worked with a reduced piston stroke and he also found the sledge system moved by a reduced amount.

The sledge system works by allowing the centre of mass of the gun to remain stationary during the firing cycle - the heavy action moves backwards a short distance as the lighter piston moves forward a greater distance. Either making the piston lighter or reducing the stroke will reduce the sledge travel.

[Garvin]

The FWB sledge and Diana Giss mechanisms:

Diana 75








FWB 300S