Now that the M82A1 has been removed, I suggest the M82A3(the same thing as the M82A1M) because it cannot be used as a sniper rifle. In .6 we had the problem of people using this gun for picking off enemies, which isnt the intended use of the weapon. So, I suggest the A3 because it is iron sights. Its could be used for the Light AT kit for the US Army. The A3 has been developed for the US army, and once they are finished we could use this kit for its original intention. We could make 1+2 magazines, with 10 rounds each. And could disable (not destroy)a small insurgent vehicle with 2 or 3 shots. In .6 we has to use a whole clip to take out a bomb car whic hwasnt realistic; but you had a scope so you could take it out at a long distance and reload and kill 10 people. So, to sum this all up: The M82A3 (without scope) could be used for Light AT purpose for the US Army would require realistic loadout, and would inflict realistic damage.
reference:
Modern Firearms - Barrett "Light Fifty" M82A1 M82A2 M82A3 Sniper Rifle

M82A3 rifle, also known as M82A1M, latest version developed for US Army. Note the long Picatinny rail on the top of the receiver.

The iron-sight for reference, not: there is no magnification, but elevation references
Caliber: .50 BMG (12.7 x 99mm)
Operation: Short Recoil, Semi-Automatic
Overall Length: 1448 mm
Barrel Length: 737 mm
Feed Device: 10 Round Detachable Box Magazine
Sights: 10X Telescopic
Weight: 12.9 kg empty
Muzzle Velocity: 854 m/s (M33 Ball)
Max Effective Range: 1800 meters
Expected accuracy: 1.5 - 2.0 MOA or better