Return Fire II - Basically the same thing but it also nullifies any lifesteal effects.

[Gboon]

Oh, you shoot me but you have leech and gun bullet lifesteal so you only take 15% of your bullet damage back? Not this time motherfucker - Return Fire II puts you in your place.
It could also have a berserker style effect. We got two headshot items, why not a second berserker item.