http://nerfhaven.com/forums/index.php?act=home the home page
http://nerfhaven.com/mods/ Some mods
Basicly you must up the psi, take out air restrictors (things that Hasbro put in the guns to dum them down so they cant get sued over an injury), Put on a new barrel (Pvc, cpvc, brass, ect.) Make new darts, put new spring-pump. ect.