Why are double mainsprings not popular for non-rotating piston springers?

[Barryg]

I have forgot the reason why they not popular and have not tried them myself, has anyone tried them in say a 77/97 with vortek type guides, they seem to make sense on paper, what's wrong with them?

[Shed tuner]

wastes a little power, not worth it. Jut swapped my FW300s from dual contra wound springs to one single, power went up, shot smoother, no hint of rotation

[Barryg]

wastes a little power, not worth it. Jut swapped my FW300s from dual contra wound springs to one single, power went up, shot smoother, no hint of rotation

Jon, I wonder why they fitted twin springs in some of the old match rifles if it wastes power, is there no advantage in getting rid of the spring torque if the piston does not rotate ?

[Shed tuner]

Jon, I wonder why they fitted twin springs in some of the old match rifles if it wastes power, is there no advantage in getting rid of the spring torque if the piston does not rotate ?

....I guess they thought it would help too

Thing is though, there's actually less action wist if the piston can't rotate - equal and opposite forces - if the piston is prevented from rotating, how can there be an opposing force on the action ?

Rotating pistons seem a smite more efficient, and let the spring wind / unwind, which I'd think was better for the springs, and possibly a little better for the efficiency (same with dual contra wound), but it actually makes it more likely that the shooter will feel action twist, not less.. imagine a really heavy rotating piston.. it's rotational inertia would be such that the piston stays still, and the action rotates around it.. Now think of the same with a non rotating (still heavy) piston - it simply can't happen.

JB

[oliver13]

It probably seemed a good idea on paper, but an extra spring adds weight & an entire layer of extra engineering to figure into the design & production.
If spring twist seems to be an issue then proper thrust bearings should sort it.
A mirror finished spring & washer with a dab of grease seem to work OK.

[Barryg]

It probably seemed a good idea on paper, but an extra spring adds weight & an entire layer of extra engineering to figure into the design & production.
If spring twist seems to be an issue then proper thrust bearings should sort it.
A mirror finished spring & washer with a dab of grease seem to work OK.

Just trying to think what you mean by extra weight and engineering in a 77/97, when it's two short springs instead of one long spring

[Snooper601]

Just trying to think what you mean by extra weight and engineering in a 77/97, when it's two short springs instead of one long spring

You have 2 extra compressed spring ends that add weight but no power and there is also the need for a guide at the joint between the springs, loads of extra weight with reduced spring room means a stiffer overall spring rate and possibly a harsher feel as a result?

Cheers

John

[Barryg]

You have 2 extra compressed spring ends that add weight but no power and there is also the need for a guide at the joint between the springs, loads of extra weight with reduced spring room means a stiffer overall spring rate and possibly a harsher feel as a result?

Cheers

John

I see what you mean about the two extra compressed spring ends

[Shed tuner]

I see what you mean about the two extra compressed spring ends

Yeah, I guess that's why the power goes up with a single... you take away the two dead compressed ends, plus the tickness of the centre TH thing, so you gain around 2.5 - 3 active coils...