This is the USMC's new MK318 MOD 0 (AKA FEDERAL T556TNB1) and MK319 MOD 0 (AKA FEDERAL T762TNB1). The T556TNB1 is a 5.56X45 caliber with a 62gr OTM and the T762TNB1 is a 7.62X51 130gr OTM.

MK318 Pricing:

MK319 Pricing:

INFO about the round:

The open-tipped rounds until now have been available only to Special Operations Command troops. The first 200,000 5.56mm Special Operations Science and Technology rounds are already downrange with Marine Expeditionary Brigade-Afghanistan. SOCOM developed the new rounds for use with the Special Operations Force Combat Assault Rifle, or SCAR, which needed a more accurate bullet because its short barrel, at 13.8 inches, is less than an inch shorter than the M4 carbine’s. Using an open-tip match round design common with some sniper ammunition, SOST rounds are designed to be “barrier blind,” meaning they stay on target better than existing M855 rounds after penetrating windshields, car doors and other objects.