Armor Piercing Ammo by Generations

AP rounds can be grouped by several notional generations.

Generation 1 is defined largely by the widespread use of hardened steel penetrators and the first tungsten AP loadings. Main contender is vehicle steel armor.

Generation 2 is defined by the widespread adoption of tungsten-core AP loads, along with the creation of SLAP ammunition. Primary purpose still in defeating light vehicle armor. GEN2 is also when clean lines were drawn in the sand between tungsten APs and "economy APs" that can be readily manufactured in wartime. 7.62x51 M61 is an example of economy AP that can be readily manufactured in wartime, while tungsten M993 is rarely issued, even if adopted. Discarding sabot rounds like 7.62x51 M948 are introduced, but design flaws prevents them from adoption.

Generation 3 is defined by the emergence of dual-core AP setups and the initial optimization of rounds towards defeating ceramic body armor plates, not just vehicle steel. Typical example is RUAG Swiss P tunsten penetrators, which are combine both tungsten and lead cores. This also marks the first pistol rounds (Libra Snail) capable of defeating entry-level rifle armor.

Another noteworthy point regarding GEN3 is that, in optimizing rounds towards defeating body armor, manufacturers begin creating AP loads in increasingly more potent cartridges as seen with .300WM AP12 and .300WM DM131. This also marks the development of "perfected" discarding sabot SLAP cartridges like .338 and .308 PTR 10, as well as the first .338 APs.

Generation 4 is defined by a global focus on ceramic armor penetration and defeating high-level body armor, in addition to pistol rounds gaining the ability to consistently defeat entry-level rifle armor. GEN4 also includes penetrators that may very well cause the body armor industry to go into a panic - .338NM SIG WC, .338NM AP529, the XMPs, the Stilettos, .338LM 7N45, 6.8mm NGSW SP, ADVAP, et cetera. For example, Stiletto's rounds utilize very large and heavy tungsten core, XMP utilize very heavy 300-grain (for .308 caliber) projectile, and HAPI rounds by Ammo inc. use its incendiary reactive charge to "weaken" armor before contact with core.

Generation 5 will most likely be defined by those penetrators which offer tungsten or DU-like performance with cheap materials. Then things like liquid tungsten or maybe Stakalloy will be a new top end. GEN5 may also include reactive metal, PELE, and FAP technologies. In UAS terms, some of such rounds are covered by Red Mercury submod.