No I get killed by the UMP a lot too. I think it's people using rapid fire (if that's still in it) - you don't get a chance to respond.
I was using it yesterday, rapid fire and kick. It's a beast. I can play this game like COD 4 with support pack running. Sod the kills and keep capturing the points, only time I bother killing anyone or to capture a point or defend one.
At least this time I get rewarded for it and can get further up the leaderboard as well.