What Is 300 Blackout Good For? Uses, Cost and a Safety Rule

Short answer: 300 Blackout is good for suppressed shooting (subsonic loads stay under the speed of sound), short-barreled AR-15s and AR pistols, and hunting medium game at moderate range with supersonic expanding loads. It puts a .30 caliber bullet in an AR-15 using the same bolt and, usually, the same magazines. It is not a long-range round, and the ammo costs more: in our catalog the median box worked out to about $1.43 a round, against $0.96 for 5.56. Never let a 300 Blackout round near a 5.56 rifle: it can chamber and destroy the gun.

What it is good for, and what it costs

Suppressed shooting

Subsonic 300 Blackout loads stay below the speed of sound, about 1,116 fps at 59°F, so a suppressor is not fighting a supersonic crack. Hornady's 208 grain subsonic leaves a 16 inch barrel at 1,020 fps with 480 ft-lb. See how suppressors work and how to buy one in 2026.

Short barrels and AR pistols

Advanced Armament Company developed the round for short barrels and suppressed use, and it runs on a standard AR-15 bolt. Barrels are usually pistol-length gas, even at 16 inches (see the gas system length chart). It is a common choice for AR pistols.

Hunting

Supersonic expanding loads such as Federal's 150 grain Fusion MSR (1,900 fps, about 740 ft-lb at 200 yards on Federal's numbers) suit deer-sized game at moderate range; check your state's hunting rules on caliber and ammunition. See can you hunt with an AR-15.

Where it falls short

Range. Hornady's 208 grain subsonic drops 33.5 inches at 200 yards from a 100-yard zero, and even supersonic loads lose energy quickly. For distance, 5.56 or .308 are better choices; compare in the 300 Blackout ballistics chart.

What 300 Blackout costs

In our catalog on 20 October 2026, 300 Blackout boxes ran from $0.60 a round (median $1.43), subsonic from $0.80 (median $1.45). 5.56 and .223 started at $0.24 (median $0.96), and 7.62x39 at $0.64 (median $0.91). A complete parts list for our 300 Blackout build totaled $642.74 that day.

The safety rule

A 300 Blackout cartridge can chamber in a 5.56 or .223 rifle, and SAAMI lists that pairing among unsafe combinations: the .30 caliber bullet cannot pass a .22 caliber bore, and firing it can destroy the rifle and injure you. Keep the ammo separate and mark your 300 Blackout magazines. More in 300 Blackout BCG and magazines.

300 Blackout ammo, with today's prices

Lowest price across the stores we track, per box:

Compare all ammo, or price a rifle in the AR-15 builder.

Frequently asked questions

What is 300 Blackout good for?

Suppressed shooting with subsonic ammo, short-barreled AR-15s and AR pistols, and hunting medium game at moderate range with supersonic expanding loads.

What is a 300 Blackout round?

A .30 caliber cartridge (7.62x35mm) developed by AAC to run in an AR-15 with the standard bolt, mainly for short barrels and suppressors.

How much does 300 Blackout ammo cost?

In our catalog on 20 October 2026, from $0.60 a round, with a median of about $1.43; subsonic started at $0.80.

Is 300 Blackout good for deer?

With supersonic expanding loads at moderate range, many hunters use it. Check your state's rules on caliber and ammunition.

Can you shoot 300 Blackout in a 5.56 rifle?

No. It can chamber, but the .30 caliber bullet cannot pass the .22 caliber bore, and firing it can destroy the rifle. SAAMI lists it as an unsafe combination.

Is 300 Blackout good for long range?

No. Subsonic loads drop about 33.5 inches at 200 yards from a 100-yard zero; use 5.56 or .308 for distance.