600 round case of newly manufactured Federal XM855 62 grain FMJ-BT cartridges in caliber 5.56 NATO. Bulk packaged in 4 boxes of 150 loose rounds. These are green-tipped bullets with steel cores and copper jackets, as used by the US Military.
These boxes of ammunition may make good trading material the next time the BATFE unilaterally decides to reclassify M855 as "Armor Piercing."
Many rifles chambered in 5.56 NATO are not realizing their full
potential when shooting 223 Rem ammo. To get all the
performance 5.56 NATO can deliver, you need a
5.56 NATO load. 5.56 NATO chambered rifles were designed to take advantage of the
higher pressure of the 5.56 NATO cartridge — higher pressure translates
to increased velocity, higher energy and harder-hitting performance.
Firing 5.56 NATO ammunition in 223 Remington chambers will produce a
dramatic rise in pressure which increases stress on the weapon, risking
wear, permanent damage and/or injury.
This is military style ammunition for your military style AR-15. This ammunition is for use only for chambers marked 5.56 NATO, as are most AR-15 carbines and rifles. Do not use it in sporting rifle chambers marked .223. M855 (M16A2) cartridge is best used with a rifling twist rate of 1:7 or 1:9. When the M855 is fired in a rifle with a slower rate of twist the longer 62-grain bullet can yaw up to 70 degrees in free trajectory through the air, substantially degrading accuracy.
Jason Nash, Group Lead, Communications - ATK Ammunition and Related Products Group: "We've had several questions regarding the XM designation and following is our official statement regarding what the product is. XM193 ammunition is 5.56mm contract overrun material. It may not meet all of the mil-spec requirements, however, it does meet all requirements of commercial ammunition for pressure, form, fit and function. Like any other mass-produced product, there are often imperfections in either appearance or non-functional mechanics. As we all know, the military is very stringent in their requirements and for good reason. This being the case, it doesn't take much to fall outside of those parameters." The Gun Zone: "What does ATK's "XM" prefix and "PD" suffix actually mean"