I use the AT4-HS (that's the name that escaped you) to take out UMVs all the time, you just have to wait for the lock on and it does the rest.
Got the Bomb Defuser, Bomb Runner, and Decimator (thanks to a care package Heli) Accolades just now with the build I posted above in Sabotage on the Afghan Map. Bunch of jerkoffs camping the entire time with one guy on my team actually talking shit about my using a shield on an "open map". Never mind I literally ran that damn bomb from our defense point to the target, twice, with little more than a throwing knife and shield bumps as my major offensive weapons, and
defused the bomb three fucking times, and this idiot wants to say I don't know how to properly use my shield and am "Fucking worthless"? Ended up with something like 15-25-6 at the end. Just me and another shield wielder even bothered running the bomb for most of the game, with three quarters of our team camping. Ugh.
Sorry, had to vent. First time I've had a bad experience with the game in MP so far though, most people I've encountered have been happy to have my "fucking worthless" shield-packing ass being the bullet sponge for the team on the objective based modes. :lol