I did this, went prone behind a sniper shield on Empire's Edge and got 5 kills. I counted and checked my kills after, I had 6, but one was a guy trying to sneak up behind me. None were assist counts as kill either. They were all actual kills.
Never unlocked. Not only do I hate hill humping, but now I have to do it again? GG DICE.
Any tips on doing this quickly? I've basically ignored doing the specializations because I never check the soldier page. Also, sidenote: what's with the hitbox on that shield? I had a hard time shooting through it unless I aimed straight forward.