Special ammo.

The point is not being an upgrade. Is just an single magazine that you can carry with “special rounds”, one magazine per spawn.

If very hard to solo a tank with K-bullets because you have only 5 of then. But with teamplay aka an recon squad using k bullets, is not impossible.

Light and heavy aren’t necessarly something “special” like an APIT(armor piercing incendiary tracer) round. IMHO

bolt action rifles should choose between AP or HE (5 of then per spawn like k bullet on BF 1)
Semi auto rifles between APIT(armor piercing incendiary tracer like on hardline) , API(armor piercing incendiary), but not explosive ammo(high ROF + area of effect damage can’t be balanced) (35 of then per spawn)
SMG/Pistol - P+ rounds (higher recoil/higher damage), hollow point(higher damage/lower penetration) (one clip / spawn )
Shotguns - Buckshot, cutshot, slugs, dragon breath, flechette, slugs armor piercing (12 of then per spawn)
LMG - One “belt” of API-AI-APIT-HE or any other combination