Mark112 wrote:Hi
.... and here goes. This:-
.... is a plot of your power curve. Depends on how you quantify the 'sweet spot' but using a 1.5% rule (12fps as shown between the orange lines on the graph) would mean you only have 23 shots. Using a 20fps figure gives 40 shots.
Comapare that to my own S410 Classic:-
..... giving 63 shots within 1.5% and 87 shots within 20fps (if it were a carbine I would expect those figures to be 47 and 65 shots respectively). The following is my shooting buddies S400 Classic:-
.... which as you can see has a curve very much like my own one and gives a very similar figures of 64 shots (1.5%) and 88 shots within 20fps. Your curve looks very different. As I hinted in my previous text one of my own rifles had this type of curve and it was fixed by replacing the firing valve, pot spring and hammer spring. I may not have needed to change the springs but did it anyway as they are only a few quid from bgaltd on this site. A chap calling himself cloverleaf has done some research into deformation of the exhaust valve and you may want to search for "valve extrusion" on airgunforum.co.uk (sorry if this breaches any conduct rules moderators) as I think you may have this problem. I had a technical thread on the previous version of the airarmsownersclub which showed the before and after effets of replacing these parts. Sadly that info was lost when the site changed hands. Parts are relatively cheap and pretty simple to fit (you already have 75% stripped your own rifle).
Hope this is of some use to you and yes I know it is a bit geeky.
Mark
So by changing the springs you mention your certain I could get a power curve similar to yours
