[Snake]

Sure needs a small ha-chop to fit in properly, Balthie would be 100% right if the curses weren't as 'easy' to inflict, but then I recall that MGs get +50 Hit for overcharging the firearm with the innate. And the only thing that can ever dodge it (25% chance) is a 72 CEL 40 LUC rabbit ST/Verglas with Fortune Wind, Southern Wind, Ninja Armor and jesus in the heart.
MG 'is' weak (damage wise) currently, but it's not enough reason to cripple the enemy's CEL/SKI by that much (and speaking of which, it also stacks with cripple leg/arm, owch). Maximum of a debuff should be 10-15, or simply what Spooks said, High Charge Power alone should be fine.

(Except this specific shell will be a bit useless in multi-shot guns. I think One Overcharge should be tweaked and I might have something in mind for a suggestion.)