Atomic Ammunition Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammo 20 Rounds. 223 Rem 77gr subsonic ammo is built for suppressed AR-15 training and quiet close-range practice. The hollow point boat tail load stays below the sound barrier to cut the crack of standard .223 while preserving practical accuracy for low-noise rifle work. Subsonic .223 is a niche load with a specific purpose: maximum noise reduction on the AR-15 platform. At 1050 fps with a suppressor you get hearing-safe shooting (under 125 dB) without the punishing crack of standard 5.56. The 77gr HP BT maintains good accuracy at close range (inside 100 yards). Note: subsonic .223 will not reliably cycle semi-auto gas systems this is a bolt-action or single-shot load. For shooters with bolt-action .223s or AR-15s with suppressor-optimized uppers its a uniquely quiet training experience. Loaded with components: new brass cases precision-weighed powder charges and 77gr HP BT projectiles. Hand-inspected to Atomics standards. Specifications for Atomic Ammunition Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammunition: Manufacturer: Atomic Ammunition Caliber: .223 Remington Bullet Type: Boat Tail Hollow Point (BTHP) Bullet Weight: 77 grain Cartridge Case Material: Brass Muzzle Velocity: 1050 ft/s Muzzle Energy: 189 ft-lbs Application: Training Features of Atomic Ammunition Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammunition Origin American-made Sound Reduction 30-40 dB w/ Suppressor Caliber .223 Rem Bullet Weight 77gr Bullet Type Hollow Point Boat Tail Case Material Brass Muzzle Velocity 1050 fps Muzzle Energy 189 ft-lbs Application Suppressed Training Quiet Practice Package Contents: Atomic Ammunition Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammunition What is Atomic Ammunition Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammunition good for? The manufacturer thinks that it is best for training.Atomic Ammunition CART-223REM-77GRSUB-20: Subsonic .223 Remington 77grain Boat Tail Hollow Point Brass Cased Rifle Ammo 20 Rounds