Gauss-accelerated piston to replace mainspring in airrifles

hardraade

I was wondering if I could match and exceed the 20-joule effect of a springpowered rifle by replacing the spring with a suitable length of iron behind the original piston, so the eddycurrents can do its thang.

I was wondering how much energy thats needed for a...say...35 joule of power in one stroke\discharge of EMP.
I want to know if its even possible to batterypower the thing without strapping on a backpack of carbatteries..
Or if it could be possible with several rechargable hicap.batterypacks for demanding softguns or small, dry marine batteries for boats that could at least partly conseal the batt.and capacitators in a hollowed out stock compartment\bracing myself for a somewhat bulky and....not sleek appearance of the rifle.