Can a heavy piston rob power?

[look no hands]

I would like to experiment with a metal top hat to increase weight but don't how much one would weigh. Any rough Ideas for a 25-26 mm cylinder?

I'll be coy about which gun I'm thinking of.

Just man up and admit it's a an HW

[Dornfelderliebe]

Just man up and admit it's a an HW

No but now the sun's out I'm going to play with my 35 later

[Barryg]

As Pete says.

But it's so easy to generalise, as said earlier. Some guns might benefit from more piston weight, others not. It depends on the design, dimensions, desired power and characteristics etc.

In the case of the TX HC item, this longer / heavier top hat increases weight, and therefore momentum and also spring preload. Many tinkerers remove this heavy steel item and substitute for a lighter acetal item, giving very slightly less initial recoil from the first compression stroke and a "quicker" feeling cycle but have to increase preload to restore power as this usually drops, thus quickening up the cycle even more, due to quicker piston acceleration (lighter piston / increased spring force). That extra preload will also come into play to combat potentially greater piston bounce displacement.

All what you say is right Tony and I don't have that piston weight in my gun but one of the reasons that it come out was because the power was too high, I only mentioned it because I thought it was an example of a heavy piston not robing power not how the gun shot, as far as I know all of the high-powered springers have heavy pistons. I do get that the UK power limit tunning is an all-round balance

[Shed tuner]

Inertia is a property of a stationary mass, Jon. A moving mass like a piston has momentum, and too light a piston reduces momentum.

picky picky.. I've misssed you Jim

Not quite. Splitting hairs, inertia is the tendency of an object to remain in the same state, either stationary or in uniform motion, resisting change.

You are my friend. Not like Jim

[Shed tuner]

So I guess the simple answer is that a heavy piston doesn't rob power unless using extremes

But just for fun I wonder what springer has the heaviest piston, my guess is a Patriot

In a mk1&2 they are too heavy, and that lump should be thrown away. With a suitable replacement spring, it becomes nicer to shoot.
However in the long stroke Mk3, they are need to maintain piston momentum with the much higher swept volume

[Shed tuner]

I would like to experiment with a metal top hat to increase weight but don't how much one would weigh. Any rough Ideas for a 25-26 mm cylinder?

I'll be coy about which gun I'm thinking of.

Your meteor needs a piston mass of around 180g all up. Weigh it and add weight to suit

[Dornfelderliebe]

Your meteor needs a piston mass of around 180g all up. Weigh it and add weight to suit

Thank you and un bon point* to John.

* As my French teacher used to say.

[MrGreengrass]

All what you say is right Tony and I don't have that piston weight in my gun but one of the reasons that it come out was because the power was too high, I only mentioned it because I thought it was an example of a heavy piston not robing power not how the gun shot, as far as I know all of the high-powered springers have heavy pistons. I do get that the UK power limit tunning is an all-round balance

Yes they do afaik.

[TonyL]

All what you say is right Tony and I don't have that piston weight in my gun but one of the reasons that it come out was because the power was too high, I only mentioned it because I thought it was an example of a heavy piston not robing power not how the gun shot, as far as I know all of the high-powered springers have heavy pistons. I do get that the UK power limit tunning is an all-round balance

Accepted, Bazzer.

[TonyL]

In a mk1&2 they are too heavy, and that lump should be thrown away. With a suitable replacement spring, it becomes nicer to shoot.
However in the long stroke Mk3, they are need to maintain piston momentum with the much higher swept volume

Yep, power in my .177 HC certainly took a nose dive with that heavier item removed, John, necessitating a fair old degree of extra preload to bring the muzzle energy back up. When I next have a play, then, maybe I might refit that heavier original item?

[muzzle]

I have an after market hw80 piston, weight is 425g has a 22mm I/D Not that i use it as such

[TonyL]

I have an after market hw80 piston, weight is 425g has a 22mm I/D Not that i use it as such

That's a big 'un!

[NickG]

That is a bigun ! My pistons are usually around 150 gms