In our group we had many a firefight whereby the combat just wasn't deadly enough, and those with even flak armour could feasibly shrug off a bolter round if a high damage roll wasn't scored. The culprit was the Toughness Bonus being subtracted from the damage in addition to the armour. We tried it without the TB and suddenly it became too deadly so we came up with this idea.
Bump up the armour value of all armour by 2 points, add TB to total wounds, and when working out combat it's just plain damage minus the modified armour value.
What are your opinions?