Use one of the following values with the "spawn [object name]" code. Note: You must already have the base weapon for the mod for it to be of any use (enable the "give all" code first if needed).

weaponmod_hyperblaster_bounce1
weaponmod_lightninggun_chain
weaponmod_machinegun_ammo
weaponmod_nailgun_ammo
weaponmod_nailgun_power
weaponmod_nailgun_rof
weaponmod_nailgun_seek
weaponmod_railgun_penetrate
weaponmod_rocketlauncher_burst
weaponmod_rocketlauncher_homing
weaponmod_shotgun_ammo