8.6 Blackout vs 458 SOCOM is a choice between two heavy subsonic cartridges with very different bullets. The 8.6 Blackout fires .338-inch bullets of 300 to 352 gr at about 1,000 fps for roughly 680 to 840 ft-lb, and it also runs supersonic loads. The 458 SOCOM in the XL configuration fires a 650 gr .458-inch bullet at about 1,010 fps for roughly 1,470 ft-lb, close to double. Chattahoochee Munitions manufactures both on the CM7S bolt action and the CM10 AR10.
8.6 Blackout vs 458 SOCOM at a Glance
| Feature | 8.6 Blackout | 458 SOCOM (XL configuration) |
|---|---|---|
| Bullet diameter | .338 inch | .458 inch |
| Heavy subsonic bullet | 300 to 352 gr | 650 gr Maker REX |
| Subsonic velocity | About 950 to 1,050 fps | About 1,010 fps (12.5 inch CM7S) |
| Subsonic muzzle energy | About 680 to 840 ft-lb | About 1,470 ft-lb |
| Supersonic option | 200 gr at 2,200 fps (SAAMI reference) | Lighter standard 458 SOCOM loads |
| Platform | AR10 or short action | Standard 458 SOCOM runs in an AR15; the XL configuration needs a short action or AR10 |
| Chattahoochee Munitions twist | 1:3 or 1:5 | 1:10 |
8.6 Blackout velocities are published by Just Cause USA and Black Butterfly Ammunition; the 200 gr reference load is from SAAMI. The 458 SOCOM figures are Chattahoochee Munitions’ 650 gr subsonic load; the CM10 averages 1,012 fps from 12.5 inches.
8.6 Blackout vs 458 SOCOM: Which Hits Harder Subsonic?
The 458 SOCOM in the XL configuration. Both run near 1,000 fps, so energy follows bullet weight, and a 650 gr bullet is nearly twice the weight of a 350 gr bullet. The 458 SOCOM’s .458-inch frontal area is larger too. In 8.6 Blackout vs 458 SOCOM subsonic terms, the 458 SOCOM is the heavier hitter; the 8.6 Blackout is the more versatile cartridge.
What Is the 458 SOCOM XL Configuration?
Standard 458 SOCOM runs in the AR15, where cartridge length is limited to 2.260 inches by the AR15 magazine. The XL configuration moves 458 SOCOM beyond that limit: longer projectiles seated less deeply reclaim case capacity for powder. Chattahoochee Munitions loads a 650 gr Maker REX to 2.802 inches for the CM7S and 2.790 inches for the CM10, and its 458 SOCOM firearms and magazines are configured for 458 SOCOM XL. Read What is 458 SOCOM XL?
Where 8.6 Blackout Has the Edge
- Supersonic option: a 200 gr bullet at 2,200 fps (SAAMI reference) for longer shots.
- Flatter path: a smaller, more streamlined bullet holds its speed better at distance.
- Lighter recoil: a 350 gr bullet against a 650 gr bullet at the same speed.
- Common parts: .308 bolt face and .308-length magazines.
Where 458 SOCOM Has the Edge
- Subsonic energy: about 1,470 ft-lb against about 745 ft-lb for a 350 gr 8.6 Blackout load.
- Bullet weight and frontal area: a 650 gr .458 bullet for hogs, deer and bear at close range.
- Factory loads from Chattahoochee Munitions: CM loads its own 650 gr subsonic ammunition.
8.6 Blackout vs 458 SOCOM Suppressors
A .338 suppressor fits the 8.6 Blackout; the 458 SOCOM needs a .458 rating or larger. On either cartridge, use an enclosed suppressor on a bolt action, and on a semi-automatic with subsonic ammunition. See 8.6 Blackout suppressor and 458 SOCOM suppressor.
8.6 Blackout vs 458 SOCOM: Which Should You Choose?
- Choose 458 SOCOM for a 650 gr subsonic bullet and about 1,470 ft-lb. Explore Terminal 458, including the CM7S 458 SOCOM SBR and the CM10 458 SOCOM AR10, and read 458 SOCOM subsonic.
- Choose 8.6 Blackout for subsonic and supersonic use in one firearm, a flatter path and lighter recoil. Explore Area 8.6, including the CM7S 8.6 Blackout short barreled rifle and the CM10 8.6 Blackout AR10 SBR.
More comparisons: 8.6 Blackout vs 300 Blackout, 375 Raptor vs 8.6 Blackout and 8.6 Blackout ballistics.
8.6 Blackout vs 458 SOCOM FAQ
Which is more powerful, 8.6 Blackout or 458 SOCOM?
Subsonic, the 458 SOCOM in the XL configuration: about 1,470 ft-lb with a 650 gr bullet against about 680 to 840 ft-lb for 8.6 Blackout.
Which has less recoil?
The 8.6 Blackout, because its subsonic bullets weigh roughly half as much at similar speed.
Can both run in an AR10?
Yes. Chattahoochee Munitions manufactures both on the CM10. Standard 458 SOCOM also runs in an AR15, but the XL configuration needs an AR10 or short action.
Which is better for hog hunting?
Both work at close range with expanding subsonic bullets. The 458 SOCOM hits harder; the 8.6 Blackout adds a supersonic option for longer shots.
Can one suppressor work on both?
A suppressor rated for .458 or larger will fit both bores. A .338-rated suppressor fits only the 8.6 Blackout.
Who makes 8.6 Blackout and 458 SOCOM rifles?
Chattahoochee Munitions manufactures both on the CM7S bolt action and CM10 AR10. Its 458 SOCOM firearms are configured for 458 SOCOM XL.