Two big-bore, straight-wall cartridges. Same bullet diameter. Very different histories, platforms, and practical strengths. If you are trying to decide between the 45-70 Government and the 450 Bushmaster – whether for whitetail in a straight-wall state, bear country, or just because you like heavy bullets – this comparison lays it out plainly.
Quick Takeaways
- Both cartridges fire 458-caliber bullets and meet most straight-wall hunting regulations, but they are not interchangeable in practice.
- The 450 Bushmaster runs in AR-platform rifles and shoots flatter with lighter bullets at higher velocity.
- The 45-70 Government thrives in lever actions and single shots, offering far more versatility in bullet weight and load pressure.
- For Midwestern deer hunters in straight-wall-only zones, the 450 Bushmaster is purpose-built for the job.
- For hunters who want one cartridge that can scale from deer to dangerous game, the 45-70 has more range.
Origins of the 45-70 and 450 Bushmaster
The 45-70 Government dates to 1873, originally designed as a black-powder military cartridge for the Springfield trapdoor rifle. It has survived longer than almost any other centerfire rifle cartridge in American history. Over 150 years, it evolved from cavalry use to buffalo hunting to modern lever-action bear defense. Today it is loaded to three distinct pressure tiers – trapdoor-safe, lever-action, and modern strong-action – which gives it a versatility that few cartridges can match.
The 450 Bushmaster is a product of the early 2000s, born from Jeff Cooper’s “thumper” concept – a big-bore cartridge that could deliver serious terminal performance from an AR-15-length action. Tim LeGendre developed the original wildcat, and Hornady refined it into a commercial cartridge. For years it was a niche round. Then states like Michigan, Ohio, and Indiana changed their deer hunting regulations to allow straight-wall rifle cartridges in zones that previously restricted hunters to shotguns. Almost overnight, the 450 Bushmaster became one of the most popular deer cartridges in the Midwest.
Ballistics Compared at Real Hunting Range
Factory loads tell the story clearly. The standard 450 Bushmaster load pushes a 250-grain bullet around 2,200 fps, generating roughly 2,686 ft-lbs at the muzzle. The standard lever-action 45-70 load fires a 300-grain bullet at about 1,800 fps, producing around 2,158 ft-lbs. If you step up to a modern single-shot or bolt action rated for higher pressures, the 45-70 can push that same 300-grain bullet to 2,100 fps and beyond, closing the energy gap considerably.
Here is what that looks like at real hunting distances:
| Metric | 450 BM (250 gr) | 45-70 (300 gr, lever) | 45-70 (300 gr, strong action) |
|---|---|---|---|
| Muzzle velocity | 2,200 fps | 1,800 fps | 2,100 fps |
| Muzzle energy | ~2,686 ft-lbs | ~2,158 ft-lbs | ~2,937 ft-lbs |
| 100-yd drop | ~2.5 in | ~5.0 in | ~3.2 in |
| 150-yd energy | ~1,600 ft-lbs | ~1,350 ft-lbs | ~1,850 ft-lbs |
| 200-yd drop | ~11 in | ~18 in | ~13 in |
At 150 yards and under – where the vast majority of Midwestern deer are taken – both cartridges hit hard enough to cleanly take any whitetail. The 450 Bushmaster shoots flatter, which matters if you are not accustomed to holding over. The 45-70 in a strong action delivers more raw energy, which matters more for elk-sized game or bear.
Platform Choices – AR vs Lever Action
This is where the two cartridges really diverge. The 450 Bushmaster was designed for the AR-15 platform. Rifles like the Ruger AR-556 in 450 BM, or builds based on standard AR-15 lowers with a modified bolt and barrel, give you a semi-automatic action, detachable magazines, and familiar ergonomics. Most 450 BM AR magazines hold 5 to 7 rounds. Optics mounting is effortless on a Picatinny rail. If you already own AR-pattern rifles, the manual of arms is identical.
The 45-70 lives primarily in lever actions and single shots. The Marlin 1895 and Henry 45-70 are the most common choices, with the Thompson Center Encore and Ruger No. 1 filling the single-shot role. Lever actions typically hold 4 to 6 rounds in a tubular magazine. They are slim, fast-handling in thick brush, and have a loyal following. The trade-off is slower reloads and fewer aftermarket optics options – though modern lever guns increasingly ship with rail-ready receivers. If you are shopping for a 45-70, look for features like a threaded muzzle for brakes or suppressors and a receiver drilled for a Picatinny rail.
Straight-Wall Hunting Laws by State
Both the 45-70 and 450 Bushmaster qualify as straight-wall cartridges, and both are legal in most states that have adopted straight-wall rifle seasons. These regulations were created to give hunters an alternative to shotgun slugs in areas where rifle cartridge range was a safety concern. The straight-wall requirement limits effective range compared to bottleneck rifle cartridges like the 308 Win.
That said, state laws are not uniform. Some states specify minimum and maximum case lengths, minimum bullet diameters, or overall cartridge length limits. Ohio, Michigan, Indiana, and Iowa all have slightly different wording. The 450 Bushmaster fits neatly within every current straight-wall regulation because it was essentially designed with those rules in mind. The 45-70 also qualifies in most states, but its longer case length occasionally raises questions. Always verify your specific state’s current regulations before hunting season. Do not rely on forum posts from three years ago – these rules change.
Common Mistakes When Choosing Between Them
Hunters making this decision for the first time tend to fall into a few predictable traps:
- Assuming the 45-70 is obsolete. It is 150 years old, but modern loads in strong actions rival or exceed 450 Bushmaster energy. Do not dismiss it because of its age.
- Buying a 450 Bushmaster for elk or bear without understanding its limitations. The 250-grain bullet at 2,200 fps is a solid deer round, but it is not a 300-grain hard-cast 45-70 load for stopping a grizzly.
- Ignoring ammunition cost. Factory 450 Bushmaster ammo typically runs $1.50 to $2.50 per round. Factory 45-70 is similar, but the 45-70 offers far more bullet weight options for handloaders.
- Not checking brass availability before committing to reload. 450 Bushmaster brass is less common than 45-70 brass. If reloading is part of your plan, factor in component sourcing.
- Choosing based on platform hype instead of hunting conditions. An AR in 450 BM is great in a ground blind. A lever-action 45-70 is great on a stalk through heavy timber. Match the tool to your actual hunting style.
- Forgetting about recoil. Both cartridges kick hard. A 7-pound AR in 450 BM with no muzzle brake will punish you. A lightweight lever gun in 45-70 with full-power loads is no picnic either. A simple upgrade is a quality recoil pad or muzzle brake – it makes a real difference in both platforms.
Quick Checklist – Which Cartridge Fits Your Situation
- You hunt whitetail in a straight-wall state from a blind: 450 Bushmaster
- You want semi-auto capability and AR ergonomics: 450 Bushmaster
- You hunt deer and also want a bear-country rifle: 45-70
- You reload and want maximum load versatility: 45-70
- You prefer lever actions and brush-country handling: 45-70
- You want the flattest trajectory under 200 yards: 450 Bushmaster
- You need the heaviest bullets available for dangerous game: 45-70
- Budget is tight and you want cheaper brass for reloading: 45-70
- You already own an AR-15 lower and want a big-bore upper: 450 Bushmaster
FAQ – 45-70 vs 450 Bushmaster Answered
Can I use 45-70 ammo in a 450 Bushmaster rifle or vice versa?
Absolutely not. Despite sharing the same 0.458-inch bullet diameter, the cases are completely different. The 45-70 is a rimmed, much longer case. The 450 Bushmaster is a rimless, rebated-rim case based on the 284 Win. They are not interchangeable in any way. Attempting to chamber the wrong cartridge is dangerous.
Which cartridge is better for whitetail deer?
Both are more than adequate for whitetail at typical hunting ranges. The 450 Bushmaster has a slight edge in trajectory and is available in faster-handling AR platforms with quick follow-up shots. The 45-70 hits harder with heavier bullets but drops more. For the average Midwestern deer hunter in a straight-wall state, the 450 Bushmaster is the more popular and practical choice.
Is the 45-70 legal in straight-wall cartridge states?
In most states with straight-wall regulations, yes. However, you must check your specific state’s current rules regarding case length and cartridge dimensions. The 45-70’s longer case has occasionally caused confusion, but it is explicitly legal in the majority of states that allow straight-wall cartridges.
Which is cheaper to reload?
Brass and component costs are similar per round, but 45-70 brass is more widely available and can be sourced from more manufacturers. The 45-70 also accepts a broader range of bullet weights – from 250 grains up to 500 grains and beyond – giving handloaders far more flexibility. The 450 Bushmaster is straightforward to reload with standard small rifle primers and no pressure-tier complexity, which is a plus for newer reloaders.
Can I hunt elk with a 450 Bushmaster?
You can, but it is not ideal. The 250-grain factory loads are marginal for elk at anything beyond close range. The 45-70, loaded with 350 to 405-grain hard-cast or bonded bullets in a strong action, is a much better choice for elk-sized game. If elk is on your list, the 45-70 is the clear winner.
Do I need a muzzle brake for either cartridge?
You do not strictly need one, but both cartridges generate significant recoil – especially in lighter rifles. A muzzle brake or quality recoil pad makes range sessions far more pleasant and improves shot placement under field conditions. If you are recoil-sensitive, prioritize this upgrade regardless of which cartridge you choose. Always wear proper hearing protection, and remember that brakes increase noise for anyone standing beside you.
