8.6 Blackout ballistics fall into two groups. Subsonic loads push 300 to 352 gr .338 bullets at about 950 to 1,050 fps for roughly 680 to 840 ft-lb at the muzzle. Supersonic loads push lighter bullets much faster: SAAMI’s 200 gr reference load is 2,200 fps, about 2,150 ft-lb. Chattahoochee Munitions manufactures 8.6 Blackout firearms at 8, 12.5 and 16 inches. This page brings the published 8.6 Blackout ballistics together by barrel length.
8.6 Blackout Ballistics Table
| Load | Barrel | Velocity | Muzzle energy | Source |
|---|---|---|---|---|
| 350 gr Maker REX subsonic | 8 inch | 950 fps | about 700 ft-lb | Just Cause USA |
| 350 gr Maker REX subsonic | 12 inch | 980 fps | about 745 ft-lb | Just Cause USA |
| 350 gr Maker REX subsonic | 16 inch | 1,040 fps | about 840 ft-lb | Just Cause USA |
| 352 gr Maker Buzz Saw subsonic | 12.5 inch, 1:3, Chattahoochee Munitions firearm | about 1,000 fps | about 780 ft-lb | Black Butterfly |
| 305 gr Maximus Fractura subsonic | 12.5 inch, 1:3, Chattahoochee Munitions firearm | about 1,000 fps | about 680 ft-lb | Black Butterfly |
| 200 gr reference load | 16 inch test barrel, 1:6 | 2,200 fps | about 2,150 ft-lb | SAAMI |
Velocities are the figures published by Just Cause USA, Black Butterfly Ammunition and the SAAMI 8.6 BLACKOUT standard. Energy is calculated from weight and velocity. Your firearm, temperature and lot of ammunition will differ, so confirm with your own chronograph. Chattahoochee Munitions does not load 8.6 Blackout ammunition and publishes no load data.
Subsonic 8.6 Blackout Ballistics
Subsonic means slower than the speed of sound, about 1,116 fps at 59°F at sea level and lower in cold air. Loads sit near 1,000 fps so they stay subsonic on cold days. At that speed, energy rises only with bullet weight, which is why 8.6 Blackout subsonic loads use 300 to 352 gr bullets. A 350 gr bullet at 980 fps carries about 745 ft-lb, roughly half again what a 220 gr 300 Blackout subsonic carries at similar speed.
The trade is trajectory. A bullet at 1,000 fps drops quickly past 100 yards, so most suppressed subsonic shooting and hunting happens inside about 100 to 150 yards. Range your target and confirm your holds on paper before you hunt. See 8.6 Blackout subsonic.
Supersonic 8.6 Blackout Ballistics
With lighter bullets the 8.6 Blackout behaves like a short .338 hunting cartridge. SAAMI’s reference is a 200 gr bullet at 2,200 fps from a 16-inch barrel, about 2,150 ft-lb, roughly three times the energy of a heavy subsonic load and with a far flatter path. Supersonic loads lose the quiet of subsonic ammunition, because the bullet itself cracks as it passes. Chattahoochee Munitions generally favors a 1:5 twist for lighter and supersonic bullets; see 8.6 Blackout twist rate.
How Does Barrel Length Change 8.6 Blackout Ballistics?
Less than you might expect with subsonic loads. Just Cause USA lists its 350 gr load at 950 fps from 8 inches, 980 fps from 12 inches and 1,040 fps from 16 inches. Going from 12 to 16 inches adds about 60 fps, and a subsonic load cannot go much faster without breaking the sound barrier. In Chattahoochee Munitions testing, powder use with subsonic loads is effectively complete at about 12 to 12.5 inches. See 8.6 Blackout barrel length.
Does Twist Rate Change 8.6 Blackout Ballistics?
Not in a way that matters for choosing a firearm. Twist controls stability, not speed. A bullet that is not stable will not group or expand as designed, so match the twist to the bullet first: with barrels of about 12.5 inches or longer, Chattahoochee Munitions testing has generally favored 1:3 for subsonic bullets of about 323 gr and up and 1:5 for about 300 gr and under.
Which Firearm Fits Your 8.6 Blackout Ballistics?
- Heavy subsonic, compact: 12.5-inch firearms such as the CM7S 8.6 Blackout short barreled rifle or the CM10 8.6 Blackout AR10 SBR.
- Subsonic and supersonic, no NFA paperwork: 16-inch firearms such as the CM7S 8.6 Blackout bolt action rifle or the CM10 8.6 Blackout AR10 rifle.
- Short package: 8-inch firearms such as the CM7S 8.6 Blackout bolt action or the CM10 8.6 Blackout AR pistol.
See every configuration in Area 8.6, and compare cartridges in 375 Raptor vs 8.6 Blackout, 338 ARC vs 8.6 Blackout and 8.6 Blackout vs 300 Blackout.
8.6 Blackout Ballistics FAQ
How fast is 8.6 Blackout subsonic?
About 950 to 1,050 fps. Just Cause USA lists its 350 gr load at 950 fps from 8 inches, 980 fps from 12 inches and 1,040 fps from 16 inches.
How much energy does 8.6 Blackout subsonic carry?
Roughly 680 to 840 ft-lb at the muzzle, depending on bullet weight and barrel length.
What are 8.6 Blackout supersonic ballistics?
SAAMI’s reference load is a 200 gr bullet at 2,200 fps from a 16-inch test barrel, about 2,150 ft-lb.
What is the effective range of 8.6 Blackout subsonic?
Most subsonic shooting and hunting happens inside about 100 to 150 yards, where the curved trajectory is easy to manage. Confirm your own holds on paper.
Is 8.6 Blackout more powerful than 300 Blackout?
Subsonic, yes, by bullet weight: a 350 gr 8.6 Blackout bullet at 980 fps carries about 745 ft-lb against roughly 490 ft-lb for a 220 gr 300 Blackout bullet at 1,000 fps.
Does Chattahoochee Munitions publish 8.6 Blackout load data?
No. Chattahoochee Munitions does not load 8.6 Blackout ammunition and publishes no load data. Use factory ammunition and the ammunition maker’s published figures.
Who makes 8.6 Blackout rifles?
Chattahoochee Munitions manufactures complete 8.6 Blackout firearms: CM7S bolt actions at 8, 12.5 and 16 inches and CM10 AR10s at 8, 12.5 and 16 inches.