When the chips are down, you shouldn't be worrying about your ammunition. PMC agrees completely and responded with their X-Tac line. X-Tac is tried and tested by military and law enforcement around the world. Each round is manufactured to the exacting specifications demanded by organizations and needed by our customers. PMC Ammo is proudly made by our allies in South Korea. Check out our bulk ammo pricing and save more when you buy in bulk. NOTE: While the 5.56x45mm NATO round will fit in a .223 Remington chamber, 5.56 NATO is a military round that runs at higher pressures, and is not recommended for use in .223 Remington chambers. Order today!