If you have downloaded the enabled devmode file, open the "devmode.lua" file with a text editor. Look for a line that reads "function AllWeapons()". Underneath it there are lines that read "AddWeapon("[weapon name]");". For example, to get the mutant shotgun edit a line so it says AddWeapon("MutantShotgun");. Note: If you put a weapon that you normally cannot get in the game you will not be able to see it when you pull it up but, you still can shoot it. You may need to use the "999 ammunition" code for ammunition for that weapon.