springer overspringing

[hmangphilly]

morning all

I've seen a couple of references to "overspringing " of springers .

Sure i get the idea of the term but , could any one expand or explain for me please .......how to recognise / rectify .
ta

[Shed tuner]

morning all

I've seen a couple of references to "overspringing " of springers .

Sure i get the idea of the term but , could any one expand or explain for me please .......how to recognise / rectify .
ta

Hard to cock, feels harsh and slammy, down on power., innacurate. Emperically, reducing preload increases power.

[18 Wheeler]

The springer equivalent of constipation.

[PCPShooter]

'too much spring', like attempting to get a BSA lightening in 177 to over 10.5ftlbs, or many hw99s too in 177 .......

[Black Beard]

It is when the piston slams in to the end of the cylinder on the forward stroke. Caused by too powerful a spring, too much preload, too much lost volume, etc.

Often found on old amateur tuning attempts involving a Ox spring, drilled transfer port and rattled fillings.

[NickG]

Too much spring, can put more pressure into the seal causing it to expand with more pressure into the cylinder walls causing drag, counter productive , ie the more spring you use the more drag you get and the power goes down

[piggy589]

As a well respected professional tuner said to me.

With regard to muzzle energy,there is an optimum spring for any gun,and that isn't the most powerful.

[Shed tuner]

Too much spring, can put more pressure into the seal causing it to expand with more pressure into the cylinder walls causing drag, counter productive , ie the more spring you use the more drag you get and the power goes down

Cardew theorised that it's also due to the excessive pressure causing the combustion effect to try to happen in the transfer port / barrel, not in the end of the comp tube.. i.e. the timing is all wrong.

[TonyL]

About a year ago a member Pm'd me about his HW80. Low power and seemingly harsh.

I suggested first port of call as the breech seal and also to check that it wasn't oversprung. When I mentioned the over springing, he did say that the thought had crossed his mind. Lo and behold, it had "far too much spring" in there. I can't remember the type. Shortening the spring restored the gun's power and improved the firing cycle.

As well as the reasons up above, as I see it, all that increased spring energy goes into too rapid piston acceleration leading to an even greater transfer port choking effect and the energy drives excessive piston bounce.

As posted above, it's all about the balance.