The AT rifle, i think, should be a team as opposed to an upgrade to a squad. And i agre with the other guys, about how it should have abilities simmilar to the PE's AT halftrack, ie ability to immobilise vehicles, rather gthan destroy them. It should however, be capable of destroying early game light vehicles, jeeps, motor bikes, and the variuous armoured cars.
with the Automatic AT rifle you could use it in the same way as the German AA tank where it has a sorta burst, then a reload time. or the burst should cost ammo, liek the mg's armoured piercing rounds?