Best 300 Blackout Ammo: Subsonic, Supersonic, and Hunting Picks

Picking 300 Blackout ammo by job: quiet subsonic for suppressors, supersonic for general use, and expanding loads for hunting where legal.

300 AAC Blackout was designed to give the AR-15 a .30-caliber option that runs well from short barrels and quietly with a suppressor. The best ammo depends on which of those jobs you care about. We cover the cartridge head-to-head in our 300 Blackout vs 5.56 comparison; this guide is about choosing loads.

Subsonic picks

Subsonic loads use heavy bullets, commonly around 200 to 220 grains, below the speed of sound. Through a suppressor they're very quiet. They also have a steep trajectory and much less energy, so they suit close to moderate range. Some rifles need a suppressor attached to cycle subsonic reliably, so test before buying a case.

Supersonic picks

Supersonic 300 BLK uses lighter bullets, commonly around 110 to 125 grains, and behaves like a short-range .30-caliber rifle round. It's the better choice without a suppressor and for longer shots. For range practice, FMJ is typical; for hunting, choose an expanding bullet.

Hunting

Supersonic expanding loads are the usual choice for deer-sized game at moderate range, where legal. Subsonic hunting bullets exist too, designed to expand at low velocity, but they demand shorter shots. Check your state's regulations and confirm your rifle's accuracy and point of impact with your hunting load before the season.

Cycling and zero

Short-barreled 300 BLK rifles and pistols may need specific gas setups to run both supersonic and subsonic. Test both types in your configuration. The two also hit very differently downrange; zero for your main load and note the holdover for the other. Our subsonic vs supersonic explainer covers why.

How much to stock

A simple 300 BLK plan

If you're new to 300 Blackout, start small. Buy one box of subsonic and one of supersonic, shoot both with and without a suppressor if you have one, and note which cycle reliably and where each hits. Then buy the winner in quantity. Label everything clearly, use distinctive magazines, and keep 5.56 out of the range bag on 300 BLK days. That routine prevents both reliability surprises and the dangerous mix-up.

Suppressed shooters should also watch for buildup. Subsonic loads can leave more carbon in the action, especially in short-barreled setups. Clean more often than you would with a 5.56 carbine, pay attention to the bolt and chamber, and follow your suppressor maker's cleaning guidance for the can itself. A rifle that ran perfectly early in a session can start short-stroking as fouling builds, so note round counts when you test reliability.

When comparing listings, check the bullet weight and whether a load is labeled subsonic or supersonic before anything else. Those two facts tell you more about how it will behave in your rifle than the brand name does. Then check whether the listing mentions a specific barrel length used for its velocity figures, since short barrels change results.

Also confirm your magazines. Most AR magazines work, but some 300 BLK owners find certain magazines feed heavy subsonic bullets more smoothly. Test yours with the loads you plan to use before a range day or hunt depends on them.

Label those magazines, too.

300 BLK costs more than 5.56 and is typically shot at a slower pace. A few hundred rounds of your main type is a good start; buy a case once you've confirmed it runs in your setup. If you use both types, keep them in separately labeled containers so you always grab the right one for the day's configuration.

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