Upgrade browning leverage

[BigD82]

I found an online site that had a great deal on the browning leverage .177 under lever rifle. I got excited and bought it but when I got it I realized that it was on sale because it was the 490fps version. Can anyone tell me if the spring from the 1000fps version will fit in this gun or if not does anyone know of another spring that would b a direct replacement and give me at least 800fps. Or if all else fails can I shim the piston to put more tension on the spring (I seen a video online of someone doing that to a different gun)? 

 

[epeyton]

I ordered a Browning Leverage .177 cal 490 fps from Walmart for $77.33.
When it is delivered, I will test it for accuracy with several pellet types and post the results.
I already have the .177 cal 1000 fps model that is very accurate with JSB 8.44 gr pellets at 870 fps.
It is more accurate than all 8 of my break barrel rifles.
If the 490 fps model is more accurate than the 1000 fps model then it will challenge my 5 PCP rifles for accuracy.
Mike at Flying Dragon Air Rifles can probably do any upgrade that you want To the Browning Leverage which is the same rifle as the XS46U.
http://www.flyingdragonairrifles.org/

 

[epeyton]

The accuracy of my Browning Leverages 1000 fps and 490 fps are about the same, therefore, I like the 1000 fps model best.