Lake City

The Raufoss Mk 211 is a .50 BMG (12.7×99mm NATO) multi-purpose anti-materiel high-explosive incendiary/armor-piercing ammunition projectile produced by Nammo under the model name NM140 MP. It is commonly referred to as multipurpose or Raufoss, meaning red waterfall in Norwegian. This refers to Nammo's precursor company Raufoss Ammunisjonsfabrikker, an ammunition manufacturer established 1896 in Raufoss, Norway. The "Mk 211" name comes from the nomenclature Mk 211 Mod 0 used by the U.S. military for this round.

This is from the only legal release of .50 bmg Raufoss Mk 211 and was purchased directly from the purchaser who bought it directly from lake city. Only 2018-2020 head stamps are allowed for civilian sales.

https://en.wikipedia.org/wiki/Raufoss_Mk_211