BudsGunShop.com - 5.56 or 223 only?

Derek. even though titled 223, the barrel is actually stamped 5.56NATO so it will handle both 556 and 223 without issue.

it will be fine with either 223 or 5.56 ammo (5.56 can use 223 but a 223 rifle can not use 5.56)

It can shoot both 5.56 and .223 rem. Info from: tombstonetactical.com/catalog/fnh/36301-fn15-sporting-ar15-rifle-5.56mm-18in-30rd-black/ . And also hyattgunstore.com/fn-fn-15-sporting-ar-15-223-5.56-rifle.html