8.6 Blackout vs 45-70: 7 Powerful Differences Compared

Updated August 2026. Figures compiled from published factory load data across both cartridges.

The 8.6 Blackout vs 45-70 question sounds like a mismatch until you look at what both cartridges are actually asked to do. Both throw heavy bullets slowly. Both excel in thick cover inside 200 yards. Both have a devoted following that considers the other one unnecessary. The difference is that 45-70 has been doing this since 1873 and 8.6 Blackout was engineered in this decade specifically to do it quietly. This comparison lays out where each one genuinely wins.

8.6 Blackout vs 45-70 at a glance

The energy answer surprises people

Here is the fact that reframes the 8.6 Blackout vs 45-70 debate: at subsonic velocities, 45-70 carries more energy. A 500gr .458 bullet at 1,000 fps produces roughly 1,110 ft lbs, against roughly 840 ft lbs for a 342gr 8.6 subsonic at 1,050 fps. Mass wins, and the 45-70 has more of it with a much larger frontal area.

Supersonic, the gap widens further in the old cartridge’s favour. Standard lever gun loads push a 300gr bullet around 1,800 to 1,900 fps for roughly 2,200 ft lbs, and heavy loads intended for strong modern actions reach 3,000 ft lbs and beyond. Supersonic 8.6 Blackout tops out near 2,000 ft lbs. On paper, 45-70 wins the energy column at both ends.

So why does anyone choose the newer cartridge? Because energy on paper is not the same as performance in the field, and the rest of this comparison is about that difference.

Twist rate: the reason 8.6 exists

If one number explains the whole 8.6 Blackout vs 45-70 divide, it is twist rate. 45-70 barrels typically run 1:20 twist. That is entirely adequate for stabilizing a heavy bullet flying nose forward, which is all anyone asked of the cartridge for 150 years. 8.6 Blackout runs 1:3, roughly seven times faster, and that difference is the whole design thesis.

At subsonic speeds, conventional bullets frequently fail to expand because there is not enough velocity to drive upset. The 8.6’s extreme spin stores rotational energy in the projectile, and fracturing and expanding designs built for it open aggressively at 1,050 fps where a conventional bullet would pass straight through. Our 8.6 Blackout ballistics chart covers the numbers behind that.

The practical translation for the 8.6 Blackout vs 45-70 decision: a subsonic 45-70 delivers more raw energy, but much of it can pass through the animal rather than transfer into it. A subsonic 8.6 delivers less energy and is engineered to dump it. Which matters more depends on the bullet you actually load, not the cartridge name.

Suppression and platform

45-70 can be suppressed, and subsonic loads exist. But nothing about the cartridge was designed for it. Case capacity is built around a long barrel and a big powder charge, factory subsonic offerings are thin, and lever guns require flat nosed projectiles that limit the options further.

8.6 Blackout was designed backwards from the suppressor. Full powder burn in about 8 inches, subsonic loads engineered to stay under the sound barrier in any barrel, projectile designs built for slow speed expansion, and a case that fits AR-10 magazines. It also runs in bolt guns and, since 2026, in lever actions, which is where the two cartridges meet most directly.

If you want a semi automatic, the 8.6 Blackout vs 45-70 comparison ends here. There is no practical semi auto 45-70.

8.6 Blackout vs 45-70 trajectory

Neither cartridge shoots flat, and both punish sloppy range estimation. Subsonic loads in either arrive by parabola: expect roughly 33 to 40 inches of drop at 200 yards with a 100 yard zero. Supersonic 45-70 does better, behaving like a stout lever gun cartridge with useful trajectory to about 200 yards, while supersonic 8.6 Blackout carries usefully to roughly 300.

Model your specific load in our ballistics calculator before hunting with either. Guessing at holdover with heavy slow bullets is how animals get wounded.

Recoil and rifle weight

Recoil is the quiet factor in the 8.6 Blackout vs 45-70 decision, and it splits by load rather than by cartridge. Subsonic loads in both are genuinely soft, closer to a heavy pistol push than a rifle punch, because muzzle velocity is low and the powder charge is small. Nobody develops a flinch shooting either one quietly.

Supersonic is a different story. Heavy 45-70 loads intended for strong modern actions produce serious recoil, and in a 7 pound lever gun they are memorable. Supersonic 8.6 Blackout is far more civil, partly because it carries less energy and partly because an AR-10 weighs more and its gas system absorbs some of the impulse. If several family members will shoot the rifle, that difference matters more than a hundred ft lbs on paper.

Cost, availability and rifles

On cost and availability the 8.6 Blackout vs 45-70 answer is simple: 45-70 wins without an argument. It is stocked in every rural hardware store in America, brass is abundant, the reloading component pool is enormous, and used lever rifles are everywhere at reasonable prices. It is a solved problem.

8.6 Blackout is a young specialist cartridge. Loads come from a handful of makers, prices reflect that, and rifles cost more. The counterweight is that everything available is purpose built for the job, and our 8.6 Blackout ammo range covers both subsonic and supersonic options in one place.

The verdict

Choose 45-70 if: you want maximum energy, cheap and universal availability, a proven cartridge with a century and a half of field record, and you do not care about shooting quietly. For dangerous game backup and brush hunting, it remains superb.

Choose 8.6 Blackout if: suppressed shooting is the point rather than a bonus, you want a short handy rifle that stays short, you value bullets engineered to expand at subsonic speed, or you want the option of a semi automatic. The comparison against 300 Blackout covers the lighter end of the same idea.

Frequently asked questions

Is 8.6 Blackout more powerful than 45-70?

No. In the 8.6 Blackout vs 45-70 energy comparison, 45-70 carries more at both subsonic and supersonic velocities thanks to heavier bullets and a larger case. 8.6 Blackout counters with an extreme twist rate that makes its energy transfer more reliably at low speed.

Which is better suppressed, 8.6 Blackout vs 45-70?

8.6 Blackout, clearly. It was engineered for it, its subsonic loads are purpose built, and short barrels give up almost nothing. Suppressed 45-70 works but fights the cartridge’s original design.

Can you get subsonic 45-70 ammunition?

Yes, generally with 500gr and heavier bullets around 1,000 fps, and it hits hard. Factory selection is limited compared with 8.6 Blackout, and bullet designs built to expand at those speeds are rarer.

Which has better recoil?

Subsonic loads in both are mild. Supersonic 45-70, particularly the heavy modern loads, produces significantly more recoil than supersonic 8.6 Blackout, which is spread across a heavier AR-10 or bolt rifle in most cases.

Which is better for deer and hogs?

Both are more than adequate inside 150 yards. Choose 45-70 for maximum margin and universal ammunition availability, and 8.6 Blackout if you intend to shoot suppressed. For the historical background on the older cartridge, the 45-70 entry covers its service history well.