450 Marlin vs 45-70: Is The Modern Cartridge Always Better?

Recognizing an opportunity to modernize the 45-70, Marlin teamed up with Hornady to release the 450 Marlin in 2000. The 450 Marlin was designed to mimic 45-70 ballistics, but also to handle higher pressures that would have destroyed older 45-70 rifles.

The 450 Marlin offers big game hunters a level of safety when handloading hot ammo. But the round has fallen out of favor in the shooting community, as most view it as unnecessary. This begs the question: Is it worth upgrading to a 450 Marlin, or is the stalwart 45-70 good enough?

In this article, we will evaluate the 450 Marlin vs. 45-70 debate to help you understand the differences between the two and give you a clearer idea of which cartridge is better for your shooting needs.

What is the difference between 450 Marlin and 45-70?

These rounds are similar to one another from a ballistic standpoint. The key difference between them is that the 450 Marlin features a belted case designed for modern firearms, whereas the 45-70 has a rimmed case designed for black powder (but which is also compatible with modern, smokeless propellant).

Cartridge Naming

One thing that can be confusing to newer shooters is the old naming system used for black powder cartridges, which is different from the conventional system for naming modern ammunition.

The 45-70 Govt, which was developed in 1873, was named after the old system. The cartridge’s original full name for the was .45-70-405, meaning:

• .45 – Nominal diameter of the bullet, in inches (i.e. 0.458”)
• 70 – Volume of the charge of black powder, in grains
• 405 – Weight of the bullet, in grains

Load Variations

The .45-70 was developed by the U.S. Army’s Springfield Armory for its new Model 1873 rifle, which came to be known as the “Springfield Trapdoor.”

The original Springfield load fired a 405 grain lead flat nose bullet at a muzzle velocity of nearly 1,400 feet per second (fps), with 1,748 foot-pounds (ft-lbs) of accompanying muzzle energy.

Although respectable in their own right, these numbers are unimpressive compared to modern 45-70 loads, which can easily surpass 2,200 fps and 3,400 ft-lbs. This disparity in performance stems from advancement in propellant technology. Modern smokeless propellant is far more potent than old-fashioned black powder.

Modern metallurgy and firearm design have allowed the 45-70 to become what many online shooting forum members refer to as “nuclear loads.” These are extraordinarily powerful and exceed pressures that older rifles can safely handle. Ruger No. 1 and No. 3 are two examples of modern, single-shot rifles capable of handling hot 45-70 loads.

Most custom ammo manufacturers specify which rifles their 45-70 loads are appropriate for.

However, this has not prevented some tragic accidents from happening. More than a couple Springfield Trapdoor rifles have been destroyed by modern 45-70 loads.

Such accidents were the genesis for the development of the 450 Marlin. Hornady and Marlin set out to create a round that would replicate hot 45-70 ballistics, but also be impossible to chamber in firearms that can’t accommodate its high pressure.

Smokeless Propellant

The advent of smokeless propellant allowed ballisticians to leverage the 45-70’s massive case capacity like never before. Less smokeless propellant is needed to achieve the same ballistic result as black powder, which meant the 45-70 could be loaded to a far higher pressure than rifles chambered for it were designed to handle.

New 45-70 lever-action rifles, like the Winchester 1886 and Marlin 1895, were designed to accommodate modern 45-70’s loads’ stout pressure.

However, after WWII, the 45-70 had all but disappeared from the United States big game hunting scene, as all manufacturers had ceased producing rifles for it by the 1960s.

Marlin introduced the 444 Marlin to fill the need for a big bore hunting cartridge created by the 45-70’s leave of absence. Resembling a lengthened 44 Remington Magnum, the 444 Marlin achieved moderate success. If Marlin had any hope of the 444 Marlin becoming mainstream, then they squashed it by reigniting interest in the 45-70 during the 1970s, when they introduced a new line of lever-action rifles chambered for it. Cowboy Action Shooting enthusiasts soon grew to favor the 45-70, thus paving the way for its resurgence in popularity – and dooming the 444 Marlin to relative obscurity.

Cartridge Specs

When evaluating two centerfire cartridges, it’s good to begin by comparing their specs.

The 45-70 Govt has no parent case, and was a unique design when it was released in 1873. In contrast, the 450 Marlin draws its roots from the .458×2” American: a wildcat cartridge based on the 458 Winchester Magnum.

One striking difference between these two cartridges is that the 45-70 Gov has a rimmed case, whereas the 450 Marlin’s is belted. The 450 Marlin’s belt is a safety measure, as it prevents the round from being mistakenly chambered in incompatible 7mm Magnum or 338 Magnum firearms.

Its belted case helps the 450 Marlin ensure adequate headspace in bolt-action rifles. However, outside of a limited run of 450 Marlin Steyr Manlicher rifles, the 450 Marlin (and 45-70 too, for that matter) is predominantly chambered in lever guns (and, to a lesser extent, single-shot rifles).

Another major difference between these cartridges are their SAAMI specs the maximum safe chamber pressures. The 450 Marlin is rated at 43,500 psi: 55% higher than th 45-70’s 28,000 psi.

Those differences aside, the 45-70 and 450 are actually fairly similar.

Both rifle cartridges’ case lengths are virtually identical. The 45-70 measures 2.10”;the 450 Marlin, 2.105”. Both rounds also share the same 2.55” overall length.

Both cartridges fire the same big bore 0.458” diameter bullets. There is a lot of bullet weight overlap between the two, with 325, 350, 405, and 500 grain bullets being the most common in factory loads. Either cartridge is capable of firing bullets weighing 200 to 500 grains.

The two rounds’ case capacities are also similar, with the 45-70 having a slight edge over the 450 Marlin: 81.8 grains H₂O vs. 74 grains H₂O, respectively.

Recoil

Recoil is an important consideration when purchasing a new rifle, as a round with heavy recoil will (A) be more difficult to control, and (B) slow the rate of accurate follow-up shots. Free recoil (an objective measure of recoil potency) is wholly determined by muzzle velocity (fps), powder charge weight, bullet weight, and firearm weight.

When loaded with 405 grain bullets, both cartridges generate around 33 ft-lbs of free recoil energy. Magnum loads by Buffalo Bore loaded with the same 405 grain bullet can produce around 47 ft-lbs of recoil, which approaches shoulder-bruising territory.

There’s no denying that these big bore cartridges have heavy recoil. Their massive powder charges and heavy bullets can be challenging for new shooters to control.

Due to its large case capacity, a wide variety of 45-70 factory loads are available to choose from. If you’re firing a Trapdoor, look for a reduced powder load that won’t destroy the rifle. If you’re firing a Marlin Model 1895 Guide Gun, then you’re at liberty to select one of the aforementioned “nuclear loads.” But whichever way you slice it, the 45-70 and 450 have strong recoil. Even “mild” factory loads deliver stout kicks.

Muzzle Velocity

From a ballistic standpoint, the 450 Marlin and 45-70 are virtually identical (so long as analogous loads are compared to one another).

We are somewhat limited on factory load options for 450 Marlin, as only Hornady and Buffalo Bore produce the ammo at the time of writing. For the purpose of this comparison we will compare Hornady LEVERevolution 450 Marlin 325gr FTX and Buffalo Bore 450 Marlin 405gr JFN.

Unlike the 450 Marlin, ample factory loads are available for 45-70. Such ammo loosely falls into three categories:

• Low pressure – Appropriate for the Trapdoor Springfield
• Mid pressure – For lever guns like a Winchester Model 1886 and Marlin Model 1895
• High pressure – For modern firearms designed to handle magnum loads

For the 45-70, we will evaluate Buffalo Bore’s low-pressure 500gr hard cast LFN, Hornady’s mid-pressure LEVERevolution 325gr FTX, and Buffalo Bore’s high-pressure 430gr LFN magnum load.

Note that Hornady’s two 325gr FTX loads give us a true “apples-to-apples” comparison of 450 Marlin vs. 45 70 ballistics.

With the exception of the low-pressure load, all cartridges’ muzzle velocities exceed 2,000 fps. The 450 Marlin 325gr FTX load has the fastest muzzle velocity at 2,250 fps, while the 45-70 magnum load’s heavier 430gr bullet came in second at 2,200 fps.

Muzzle Energy

Muzzle energy is where these rounds really shine. The 45-70 and 450 Marlin are incredibly powerful rounds, with each factory load having more than 2,800 ft-lbs of energy. The Buffalo Bore 45-70 430gr load has the highest muzzle energy at a whopping 4,620 ft-lbs, while the 450 Marlin 405gr load comes in close second at 4,351 ft-lbs..

Continue reading 450 Marlin vs 45-70: Is The Modern Cartridge Always Better? here

Source: https://freedombunker.com/2025/04/17/450-marlin-vs-45-70/