Which M2, .50 caliber machine gun round is used against light armored vehicles and aircraft?

The MK211 Mod 0 round is designed specifically for use against light armored vehicles and aircraft. This round features a multi-purpose projectile that combines a hardened steel core with a plastic polymer body, giving it the ability to penetrate armor effectively while also producing a significant destructive effect upon impact. Its versatility allows it to be utilized in various combat scenarios, making it a suitable choice for engaging both ground and aerial threats.

In contrast, the other rounds listed do not possess the same anti-armor capabilities. The M1A1 and M2 rounds are primarily suited for general purpose use, including engagements against soft targets. The M33 is an API (Armor Piercing Incendiary) round, which is effective against light armor but lacks the advanced features of the MK211 Mod 0 that significantly enhance its lethality and effectiveness against more resilient targets.