Combi-weapons
These are basically two weapons joined together, giving the character a choice of two weapons to fire instead of one. A character who is armed with a combi-weapon may choose which of the weapons he is going to use in the Shooting phase. The bolter may be fired any number of times, but the other weapon may only be fired once per battle. Note that you may not choose to fire both weapons at once.
Combi-weapon: Bolter-stake crossbow
This fires a blessed silver stake that immolates its target in a burst of holy fire. The stake-crossbow is an Assault 2 weapon with a range of 24". Any psyker hit will be wounded on a 2+ and receives no Armour save (though Invulnerable saves may be taken as normal). On any other target, the weapon counts as Strength 3, AP5.