EMP ammo does does double damage to shields, 1/3 damage to health. EMP ammo delays shield regen by an additional 3 seconds. EMP ammo also disables the target's mini-map, directional damage indicators, and enemy dorito indicators for 10 seconds. Available on all sniper and scout rifles. I think this would be an excellent group support utility. Softens up, disrupts, and disorients the enemy from range, sacrificing 1-shot capability and dps overall.
The TTK in this game is too short for EMP effects to matter. If you really want a powerful support ability, denying enemy medics the ability to revive or heal targets that you shoot would be just about the only thing worth sacrificing damage potential over.
Ello Dr. and it might be slightly over powered due to the fact that shields take the majority of the beatings when being shot at. Though it might be good as a certing for utility slot.
Some other considerations: Disables the steering mechanism of Vehicles & MAXes for 1-2 seconds (certable). Wouldn't affect Libs & MBT's barely at all but it would likely be guaranteed death to ESF's who p***ed us off and that's what's needed most still when it comes to AV support.
