Slamming or bouncy

[TonyL]

With the lighter pellets, the power is too close to 12 for comfort. So instead of lopping off the spring I could increase piston weight or open the TP slightly.
But which is it?
According to the information I read my rifle is a little bouncy.

Mmm, depending on other factors also, Neil, increasing piston weight or opening the TP might cause it to produce even more power.. Unless the TP is already at its upper size limit, in which case creating that bit more lost volume might help drop the power.

I'd be tempted to source a different, softer spring, or to shorten the existing one a little (although the latter approach will make the spring stiffer). Either way will also result in easier cocking. If you already have minimal preload, I'd definitely go longer / softer spring, as too little preload will likely result in increased piston bounce.

[TonyL]

What rifle(s) are we concerned with here, Neil?

Only asking as, if it is a model with a large swept volume it may be that you may need to reduce the stroke if you wanted to retain a "quick" as opposed to "lazy" feel to the action. For example, guns like the Weihrauch HW80 and Diana 52 are notoriously tricky to keep safely below if retaining standard bore and stroke and preferring a "quick" feel.. Extreme examples, admitted.....

[Neil54]

The two rifles I happened to try are Kral devil's, same chassis as the Gamo Hunter, meteor mk6 and smk 19.
25mm bore.
I have a .177 with only 4mm preload, so this one I think i will short stroke.
The other is a .22 and has had nothing done yet. Still twangy.

My original question was should I try to get even power with light and heavy pellets.

It actually shoots quite well.

[maximus]

I personally wouldn't worry too much if it shoots nice with the lighter pellets. I have also left a gun cocked for a few hrs (obviously with no pellet in) to knock the power back a bit. Easier than chopping springs and doesn't increase the stiffness.

[TonyL]

I personally wouldn't worry too much if it shoots nice with the lighter pellets. I have also left a gun cocked for a few hrs (obviously with no pellet in) to knock the power back a bit. Easier than chopping springs and doesn't increase the stiffness.

The two rifles I happened to try are Kral devil's, same chassis as the Gamo Hunter, meteor mk6 and smk 19.
25mm bore.
I have a .177 with only 4mm preload, so this one I think i will short stroke.
The other is a .22 and has had nothing done yet. Still twangy.

My original question was should I try to get even power with light and heavy pellets.

It actually shoots quite well.

Fully agree with Max re not getting too hung up about balancing the power output between light and heavy pellets, as said before.

Max - good thinking re leaving the gun cocked for a long period to weaken it a bit.. However, with only 4mm preload to start with, conditions are rife for surge. So a longer, softer spring or short stroking it look to be the avenues to explore.

Neil, thank you for letting us know the make and model. I suspected (but didn't know, having no first hand experience) that these were based on the ubiquitous Gamo platform. One which I very much like. The Krals do look to offer very good value. What were your findings regarding internal build quality and finish?