Only Class IV body armour would protect against 7.62 NATO at such a short distance, almost nobody is issued Class IV body armour. FLAK jackets are more like Class II (will stop 9mm Para and 9mm Mak from a distance). Both the FLAK jackets and PASGT helmets will provide absolutely no protection from 5.45mm or 5.56mm in ranges under 400 meters, 7.62mm will zap straight through it from more than 500 meters. I.e., body armour should be able to "reduce" lethality in the game due to less penetration, but the player should in every situation in which he is shot with anything other than a pistol round be severely injured, and die from wounds if not treated.
Pistol rounds shouldn't work on center of mass hits on an armoured opponent though.
Another thing that bugs me is the ability to shoot through the canopy of gunships and fighter jets. Almost all of them are rated bullet proof up to 12.7mm ball, so without armour piercing rounds, nothing much would happen if you try to shoot the pilot. Right now you can even shoot him wit 9mm Para!