This is a CrazyIdea (TM) thread arising from a combination of thoughts in the shower and thoughts in the car while sitting in traffic.
It arises from the discussion Nathan and I were having in the other House Rule thread about Burst and Automatic fire allowing Spread as a Momentum spend.
The initial thought is "wow, armor sure seems minimal compared to gun damage, especially when you add in Momentum spends." I understand this is intentional and indeed, do not want to overly change the balance. What I am interested in though is creating a bit more differentiation between small and large guns. To that end, I present the following simple rule:
When spending Momentum to add directly to damage, you may not spend more Momentum than a weapon's static damage modifier plus half its dice of damage (round down). You may spend excess Momentum on OTHER momentum spends, just not pure damage. For purposes of this limit, include any Strength-based damage bonuses, but do NOT add Awareness-based damage bonuses for ranged weapons.
Example: A Piranha handgun deals 1+3DS. 1+(3/2, round down)=2. So a character shooting a Piranha can deal no more than 2 bonus damage directly with Momentum (nothing would stop a character from using Devastating Blow, however). On the other hand, a Mephisto sniper rifle deals 2+5DS damage, allowing up to 4 Momentum to be used to directly add to damage.
This idea arose from actual play. When you add in a Group Momentum pool, it becomes easy to generate A LOT of Momentum and eek 13 damage or so from a Piranha (which happened--poor Castigator). I realized that didn't feel quite right, especially because the heaviest personal armor is only 5 Soak. A character with no Awareness bonus to damage and a Piranha will deal an average of maybe 4 damage. That seems fair.