@NoahWard Damage is 29 in tooltip while in game it's only 27 and it's been this way for months you can test it in the garrison on the nids to see this or test it on a player to see that it's still only 27 damage.
The nids in the garrison have more than 100 toughness, thus reducing the damage of the Big Shootah. That it still deals 27 indicates it would deal the right amount of 29 to targets without toughness. Try shooting at the nid with a CQC barrelled Shootah and you will notice that it only deals 28 damage, even though to targets with no toughness it would deal 31.