If it's a edit and you're gonna release it... For God's sakes. DON'T.
But did you change namecheck.txt too? And archived the file as a name different than Weapon_Gun?
Also, ctrl+f in the .cs, ctrl+f, go to Replace, type in the first box gun and second biggun then replace all, so it will have nothing related to gun, but as long as you'll use the same model.. There may be some problems I do believe.