AR-15 ammo prices

The AR-15 is a platform, not a cartridge. Most rifles ship chambered in 5.56 NATO or .223 Remington, and a barrel or upper swap moves the same lower to .300 Blackout. Which one you feed determines your cost per round more than any other single factor, so the prices below are broken out by chambering rather than by rifle.

5.56 NATO and .223 Remington are the volume chamberings and the cheapest way to shoot an AR-15. A 5.56-chambered barrel will fire both; a .223-chambered barrel is rated for .223 only, because 5.56 is loaded to higher pressure with a longer throat. If your barrel is marked 5.56 or .223 Wylde you can shop both lists and take whichever is cheaper per round. M193 55gr and M855 62gr are the two mil-spec FMJ loads that anchor the budget tier; 5.56 vs .223 covers the pressure and chamber differences in full.

.300 Blackout costs roughly twice as much per round and exists for a different job: it reaches full velocity from a short barrel and has a subsonic load line built for suppressor use. It shares magazines and bolt with 5.56 but not barrels.

Ranges below are observed across tracked online retailers and update daily. For load-by-load selection rather than pricing, see AR-15 ammo by use case and the 5.56 ballistics chart.