M228 Semi-Armor-Piercing High-Penetration

The 12.7x40mm M228 Semi-Armor-Piercing High-Penetration (abbreviated M228 SAP-HP) is a type of .50-caliber round used in the M6 series sidearms.

It is somewhat rare and more of an exotic round due to its rarity of use compared to the M225 SAPHE.

Due to the semi armor piercing nature of the round it is likely coated in a hard metal such as steel but deforms shortly after impact to prevent the bullet exiting the body and causing accidental casualties. The filler is likely a hard or heavy metal, such as tungsten, which would provide the extra force and penetration this round boasts of.