PMC 556X: The X-Tac round from PMC ammunition company is a premium quality 5.56 NATO caliber round featuring a 55-grain bullet. This is a high-performance penetrator round. Hard-hitting and exceptionally accurate this is the same round that PMC produces for law enforcement, defense contractors, and competitive shooter around the globe. When you are not willing to sacrifice quality, go with PMC X-Tac. This ammunition is packaged with 20 rounds in a commercial box and 50 boxes in a 1000 round case. We sell it under this SKU by the 20 round box with a price break at the 50 box ( 1000 Round Case ) quantity.