600 rounds of newly manufactured Winchester M855 62 grain "penetrator" 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 manufactured for and used by the US Military.
Olin Winchester is now the operator of the Lake City Army Ammunition Plant where these cartridges are produced.
This ammunition was nearly banned when the BATFE under Obama unilaterally decided 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.