Tactical Expertise

Use this Stratagem at the start of your Movement
phase if the Tactical Doctrine is active.
Until the start of the next battle round, when resolving an attack made with a Rapid Fire or
Assault weapon by an ULTRAMARINES
model from your army, on an unmodified wound
roll of 6 the Armour Penetration characteristic
of that weapon is improved by an additional 1
for that attack. You can only use this Stratagem
once per battle.