5.56 NATO 77gr Cycling HP BT Defense

Atomic Ammunition’s AD77 is a precision-loaded 5.56 NATO 77gr Cycling HP BT defensive round built on the 77gr OTM profile that set the standard for 5.56 terminal performance. Purpose-built for home defense, duty carry, and 3-Gun, delivering sub-MOA accuracy, superior terminal effect, and better barrier performance than standard ball ammunition.

Atomic Duty. AD77.

The AD77 is Atomic’s purpose-built 77gr OTM (Open Tip Match) defensive load for the AR-15 platform. The 77gr boat tail profile is the benchmark for precision 5.56 engagement — selected for its superior accuracy, terminal effect, and barrier performance over standard 55gr and 62gr ball ammunition. Atomic loads it to a higher standard.

Every AD77 round is built with new-production brass, match-grade 77gr HP BT projectiles, and precision-weighed powder charges, inspected for the tight tolerances required to deliver sub-MOA accuracy and consistent 2,750 fps muzzle velocity across every lot.

Why the 77gr OTM profile?

Heavier bullet, higher ballistic coefficient. That means less wind drift, more energy retained at distance, and effective terminal performance out past 600 yards. The hollow point boat tail provides controlled expansion while reducing deflection through intermediate barriers like drywall and auto glass. The 77gr OTM isn’t new, it’s the spec that proved what 5.56 could do when loaded right. The AD77 is Atomic’s answer to how it should be loaded.

Built for: Home defense, duty carry, and 3-Gun competition. Optimized for 1:7 and 1:8 twist barrels.

Frequently Asked Questions