That would nerf its damage since explosive rounds take about. 25% of the base impact damage and convert it to aoe. the crit multiplier then multiplies by the reduce impact damage. So if it did 100 impact, explosive rounds would make it 75 on impact plus 25 aoe. The crit multiplier would then multiply by the 75 impact damage. So say it's the crit multiplier is .5 then 100 x .5 = 150 damage but with explosive rounds it would be. 75 x .5 = 118 + 25 = 143 damage It might not seem like much of a difference but once you start adding pve multipliers it makes a difference. Similar to spike grenades for grenade launchers. It's only a 2% damage buff it makes a difference in dps.