Super Shotun except Deafult Shotgun in Ultimate Doom Thread - Brutal Doom mod for Doom

I want to play in Ultimate Doom Compaign with super shotgun. I tried to add "RandomSpawner" actor in DECORATE, that instead a shotgun with 50/50 chance spawned SSG, but it dosen't work.

This is code from DECORATE:

actor STShotgunReplacer : RandomSpawner
{
DropItem "Shot_Gun", 255, 3
DropItem "Shot_Gun", 255, 2
DropItem "SSG", 255, 3
DropItem "SSG", 255, 2
}

how to do it?

Edit: I do know English not very good, in the title I wanted write "instead", but no "except"

Edited by: Black_Stalker502