no problem I would suggest to you the Laserweapon from the ratsoft "waffentutorial"
But its german!

http://www.rat-soft.de/dload/Waffentutorial.pdf

look at:"Energiewaffen" at page 26,27 and 28
it shows you an thunderlike weapon that burns !
don't know if this is what your looking for,but i think it could be easy modify!