ok, then as i said, use the 5th row, and use lacerate->tagteam->regroup->defend->firearms->trueshot. you mainly need to wait for the bleeding damage to outdamage it's healing.
it is a weapon for britt. if you have it in your bag its likely that brittis already using a weapon of the same or a higher grade. you can see britt's used equipment in the combat screen that is in the top right part of the map. you can turn 1 power into 3 scraps in the area to the left of the garage.