Yes, they make subsonic 308 ammo, and it does something a standard 308 load can’t. It keeps the bullet below the speed of sound, so there is no supersonic crack downrange. Paired with a suppressor, it turns a loud rifle into a much quieter one. But it gives up a lot of speed and energy to get there. This guide covers what subsonic 308 ammo is, the loads we carry, and where it does and doesn’t make sense.
What Makes a 308 Load Subsonic?
Sound travels at roughly 1,125 feet per second at sea level on a mild day. It moves a bit slower in cold air. A bullet that flies faster than that makes a small sonic boom along its whole path. You hear it as a sharp crack, even with a suppressor on the muzzle.
A subsonic load keeps the bullet under that line. To keep energy up, makers use heavy bullets, often 175 to 200 grains. A normal 308 load runs far faster. For example, the Remington Core-Lokt 150 grain lists 2,820 fps and 2,648 ft-lbs.
Subsonic 308 Loads We Carry
All numbers are the makers’ published muzzle figures. Click a load to see its product page.
| Load | Bullet | Grain | Muzzle velocity (fps) | Muzzle energy (ft-lbs) | Pack |
|---|---|---|---|---|---|
| Atomic Subsonic 308 Match 175 Grain JHP | Jacketed Hollow Point | 175 | 1,050 | 428 | 100-round box |
| Winchester Subsonic 308 Super X 185 Grain Power-Point JHP | Winchester Power-Point Jacketed Hollow Point | 185 | 1,060 | 461 | 20-round box |
| Winchester Super Suppressed 308 185 Grain JHP | Jacketed Hollow Point | 185 | n/a | n/a | 200 rounds (10 boxes of 20) |
| Lapua Subsonic 308 200 Grain FMJ | Full Metal Jacket | 200 | 1,066 | 506 | 20-round box |
| Sellier & Bellot 308 Subsonic 200 Grain MatchKing HPBT | Sierra MatchKing Jacketed Hollow Point Boat Tail | 200 | 1,000 | 444 | 20-round box |
The Atomic 175 grain Match JHP lists 1,050 fps and 428 ft-lbs. The Winchester Super X 185 grain Power-Point lists 1,060 fps and 461 ft-lbs. The Lapua 200 grain FMJ lists 1,066 fps and 506 ft-lbs. The Sellier & Bellot 200 grain MatchKing lists 1,000 fps and 444 ft-lbs. The Winchester Super Suppressed 185 grain JHP comes in a 200-round pack; see the product page for its specs.
What Grain 308 Is Subsonic?
Grain weight alone doesn’t make a load subsonic. The powder charge does. Any bullet can be loaded slow. Still, subsonic 308 ammo almost always uses heavy bullets, because a heavy bullet carries more energy at the same low speed.
Don’t assume a heavy standard load is subsonic. A 180-grain hunting load still runs far above the speed of sound. Buy ammo that is labeled subsonic.
Why Shoot Subsonic 308 Ammo?
- Less noise with a suppressor. No sonic crack means the suppressor can do more of its job.
- Less recoil. Lower speed means a softer push.
- Training and pest control. Some shooters use it on private land where noise is a concern.
Without a suppressor, the muzzle blast is still loud. Wear hearing protection either way.
Suppressors are regulated under federal law. State and local laws on owning them and on hunting with them vary. Check your rules before you buy.
Things to Know Before You Buy
Semi-autos may not cycle
Subsonic loads make less gas pressure. Many gas-operated rifles, like AR-10 types, won’t cycle fully on them without an adjustable gas system. Bolt-action rifles have no such issue. Test a few rounds before you rely on them.
Twist rate and stability
Heavy bullets need enough spin to fly straight, and they spin less at low speed. A rifle with a slow twist may not stabilize them. Check your barrel’s twist rate and the ammo maker’s guidance.
A very curved path
At these speeds the bullet drops fast. Your rifle will hit far from your supersonic zero. Re-zero for subsonic ammo, and keep shots close. We don’t print drop numbers here, so confirm your own at the range.
Will Subsonic 308 Kill a Deer?
It can at close range with good shot placement, but it is not ideal. Energy is a fraction of a standard load. Compare the Atomic subsonic’s 428 ft-lbs with the Core-Lokt’s 2,648 ft-lbs. Most bullets also open less at low speed, so the wound is smaller.
If you hunt with subsonic ammo, keep shots short and pick a load built to expand, such as a hollow point. Many hunters reserve it for hogs or varmints at close range instead. Some states set rules on calibers or energy for big game, and suppressor hunting rules vary, so check your state’s hunting regulations first.
Other Quiet .30 Caliber Options
If quiet shooting is your main goal, look at the 300 Blackout too. It was built to run both subsonic and supersonic loads in an AR-15. Our 300 Blackout gel test guide covers how to read its results. For standard 308 loads, see the 308 Winchester ballistics guide.
Shop Subsonic 308 Ammo
Browse our subsonic 308 ammo collection, or see every load in the 308 ammo category.
Frequently Asked Questions
Do they make subsonic 308 ammo?
Yes. Several makers load the 308 Winchester below the speed of sound, usually with heavy 175 to 200-grain bullets. In our stock, the Lapua 200 grain FMJ lists 1,066 fps and the Atomic 175 grain JHP lists 1,050 fps. Look for ammo labeled subsonic.
Will subsonic 308 kill a deer?
It can at close range with careful shot placement, but it carries far less energy than a standard load, and bullets open less at low speed. Keep shots short, use an expanding bullet, and check your state’s rules on calibers and suppressor use for hunting.
What grain 308 is subsonic?
No grain weight is subsonic by itself; the powder charge sets the speed. Subsonic 308 loads usually use heavy bullets from 175 to 200 grains so they keep more energy at low speed. Always buy ammo marked subsonic rather than guessing from bullet weight.
Is subsonic 308 good for hunting?
It is a niche choice. It suits close-range hogs and pests, especially with a suppressor. For deer and larger game, a standard load is the better tool. Laws on hunting calibers, energy and suppressors vary by state, so check your rules first.
Why shoot a 308 subsonic?
The main reason is noise. With a suppressor, subsonic ammo removes the sonic crack, so the rifle is much quieter. It also kicks less. The trade-offs are lower energy, a curved path and possible cycling problems in semi-auto rifles.
