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