First make sure the code -dev is on then push ~. And create your own game.And type in sv_cheats 1.Then type in witch weapon you want here is a list.

auto cannon-ac
rocket launcher-rpg
medic kit-medikit
knife-knife
super shotgun-supershotgun
flame thrower-flamethrower
railgun-railgun
remote pipe bomb-pl
grenade laucher-gl
wrench-spammer (i havent gotin it to work so try it out)