The Hornady Frontier Cartridge series brings reliable 223 Rem/5.56 NATO ammo to the range, offering 55 gr full metal jacket performance with brass cases and military-grade components that shooters trust for training, plinking, hunting, law enforcement drills, and personal defense scenarios. With a listed muzzle velocity of 3240 fps and muzzle energy around 1282 ft-lbs, this Hornady 223 Rem FMJ load delivers flat trajectories and consistent impact for zeroing rifles, conducting high-volume marksmanship practice, or building confidence in service-style drills. The FMJ profile feeds smoothly in semi-autos and bolt guns, traces point-of-impact for target work, and functions well through a broad range of platforms chambered for 223 Rem or 5.56 NATO, while the Frontier series emphasis on consistency supports repeatable accuracy and predictable recoil impulse during follow-up shots. If youre a range owner running training, a hunter sighting in a varmint rifle, or a serious shooter stocking reliable target ammo, this Hornady Frontier 223 Rem 55 gr FMJ option is a versatile choice that balances performance, reliability, and compatibility across common rifles and shooting applications.