An AR Rifle in .45-70?: Good Cartridges Never Die

Check out the new AR from Phoenix Weaponry chambered in this 150-year-old cartridge, and get a brief history of the .45-70 Government.

The "Christine" rifle from Phoenix Weaponry chambered in .45-70 Gov't.
The "Christine" rifle from Phoenix Weaponry chambered in .45-70 Gov't.photo from recoilweb.com

The .45-70 rifle cartridge, often referred to as 45-70 Gov’t, has been around since it was designed for the Springfield Model 1873, or the “trapdoor Springfield” which was the U.S. Army’s primary rifle until 1893.

One would think that a cartridge, especially a rifle cartridge, from such a bygone era wouldn’t have survived through almost 150 years of ammunition and firearms innovation, but it has remained a popular option for cowboy-action shooters, lever-action rifle lovers, and a significant segment of hunters. Now, a new rifle from Phoenix Weaponry brings the old-school cartridge into the 21st century with an AR-platform rifle chambered in .45-70 Government.

AR-platform rifles are produces in a wide menagerie of calibers that grows every year, but according to this story from recoil.com, this is the first time an AR has been chambered for the classic cartridge.

The story says the rifle, named “Christine,” begins with a .308 billet aluminum receiver set, a standard .308 bolt carrier group, and is finished off with a Douglas 21-inch 4140 1:14 twist .45-70 barrel.

A .45-70 cartridge (center) compared to a .223 Rem / 5.56 NATO round (left), and a .308 Win / 7.62 NATO (right).
A .45-70 cartridge (center) compared to a .223 Rem / 5.56 NATO round (left), and a .308 Win / 7.62 NATO (right).photo from recoilweb.com

But there’s a catch: while the .45-70 works fine in lever guns with tubular magazines, the rims on the cases are a no-go for a detachable-box-magazine fed rifle. So, Christine needs to be fed modified, rimless .45-70 ammo.

From a release:

“Phoenix Weaponry (has) blown the lid off the marketplace with a unique twist to this classic cartridge as they have rebated the rim so that it can be adapted to a standard .308 bolt head and fired through a high-pressure AR platform with shocking, sub MOA results, and boosted performance curve.”

Because of the basic non-existence of rimless .45-70 components, you won’t be able stop off at BassPro for some ammo on the way to the range, but for reloaders, it will be a bit easier. The company says the case, once rebated, can be reloaded easily with existing load info for the .45-70, plus standard .45-70 die sets can be used, along with a .308 shell holder.

The ammunition is fed from a modified Magpul 10-round magazine, which holds 6 rounds of .45-70.

This story from TheTruthAboutGuns.com says factory brass will be available soon and available for purchase from Phoenix Weaponry. Additionally, each rifle will come with 50 pieces of brass to let you get started.

The new rifle can only use specially modified, rimless .45-70 cartridges. The rifle comes with 50 modified shell casings to get reloaders started.
The new rifle can only use specially modified, rimless .45-70 cartridges. The rifle comes with 50 modified shell casings to get reloaders started.photo from recoilweb.com

The new rifle includes a custom trigger and muzzle brake and weighs in at just over 9 pounds, unloaded, without an optic or accessories—not a lightweight.

And the price tag is…a bit upsetting at a solid $4,800, but that includes a bunch of custom options that can be added. If you love the .45-70 and have that kind of scratch in your gun budget, then go here for more information.

If not, here’s a little history on the .45-70 Government below.

A Little .45-70 History

The round was designed as a replacement for the .50-70 Government cartridge, which had been adopted in 1866, as a sort of stop-gap cartridge, just one year after the end of the Civil War.

The full name of the original cartridge was .45-70-405, with a numbering scheme that indicated three properties of the cartridge.

The first number, .45, is the nominal diameter of the bullet, measured in decimal inches (0.458 inches or 11.53mm); the second number, 70, is the weight of the black powder charge used, measured in grains (4.6g); and the weight of the lead bullet, 405, also measured in grains (25.2g).

Using these original loads with the 1873 Springfield produced a minimum acceptable accuracy of 4 inch groups at 100 yards.

The heavy, slow-moving bullets had what is referred to as a “rainbow trajectory,” with the bullet dropping considerably at ranges beyond 300 yards required a lot of holdover for anything beyond that. However, a good shooter firing at known ranges could hit 6x6’ targets at 600 yards, which was mostly used for volley fire.

In addition to the Springfield trapdoor, it was used in double rifles like the Colt 1878.

In 1879, a new variation of the cartridge was produced, the .45-70-500, which fired a heavier 500 grain bullet which produced significantly superior ballistics, now able to reach ranges of 3,350 yards with an effective range of about 1,000 yards.

That means shooters could only fire on an individual target at 1,000 yards or less, but the heavy bullet could still produce lethal injuries at 3,500 yards.

The rounds issued for the Springfield Trapdoor rifle used a copper center-fire case design. A .45-70 “forager” round was also issued, which was topped with a thin wooden bullet filled with birdshot.

It was intended to be used by soldiers to supplement their rations by hunting small game. It basically made any .45-70 rifle into a .410 shotgun (the diameter of the .410 is the same as the .45 Colt, which is why guns like the Taurus Judge and S&W Governor can fire both).

The .45-70 was also used in several Gatling gun models until the .30 Army and M1893 Gatling gun came along.

When the Army realized the era of single-shot black powder rifles for combat were quickly being outmoded, the Springfield trapdoor was replaced with the Springfield Model 1892 in .30 Army, but the .45-70 remained in service with the National Guard, Navy, and Marines until 1897.

It was last used in any significant quantity during the Spanish-American War, but hunt around well in to the 20th century.

Today, the U.S. military still uses the .45-70 in the form of a blank cartridge used by the Army and Coast Guard in a number of line-throwing guns. Early models of these guns, used to literally launch a projectile trailing a line, were made from modified trapdoor and Sharps rifles, and later models were built on break-action single-shot rifles.

Outside of the military, the .45-70 was a big hit with American hunters and remains so. The traditional 405-grain load is adequate for any North American big game, within it’s range limitations of course. One of the bonuses is the fact that it has enough power to take on large bears, but also destroys less meet on a smaller animal, like a deer, because of the bullet’s low velocity.

Because of it’s range limitations, it’s often chambered in brush guns for hunting in heavy timber.

When it comes to custom handloads, the .45-70 has been used to take the African “Big Five” and has been loaded to harvest anything from birds to elephants.

And as the rimless rounds from Phoenix Weaponry show, new innovations are still coming for the .45-70 all these decades later.

Today, Thompson Center Arms offers a .45-70 in both pistol and rifle lengths in its Contender series of single-shot firearms. To show how powerful the old round is, even in the shortest barrel length of 14 inches, it produces well over 2,000 ft-lbs of energy—about double the juice of most .44 Magnum loads. That comes with some significant recoil, but modern muzzle brakes help tame it.

In fact, the .45-70 Contender stood mostly alone as a big-game capable handgun for quite a while until the release of ultra-magnum revolvers like the .500 S&W Magnum.

Phoenix Weaponry "Christine" Rifle Specs
Caliber: Modified rimless .45-70 Gov't
Upper Receiver: Precision CNC machined and trued from billet 7075-T7 aluminum, 1913 Picatinny flat top rail section, slick-side style(removed forward assist and brass deflector), and machined for mil spec dust cover
Lower Receiver: Precision CNC machined and trued from billet 7075-T7 aluminum.
Barrel: 4140 Chromoly18″ 1/14 twist Duglass Airgage Button Rifled 8 Grouves Ultra Rifling Custom Profiled Barrel
Gas System: Direct impingement, Phoenix Weaponry custom designed and built, light-weight, ultra-low profile, stainless steel adjustable gas block. Rifle length gas tube
Handguard: 15”, lightweight, free-floating, modular handguard. Proprietary barrel nut with screw lock mounting system for increased stability and strength
Dust Cover: Billet dust cover when closed is flush with rest of receiver completing the slick side look
Muzzle Device: Phoenix Weaponry “Chevron” muzzle brake, CNC machined from 4130 chromoly
Bolt Carrier Group: Standard .308 Bolt Carrier Group
Trigger Group: Phoenix custom 3-pound trigger
Charging Handle: Standard .308
Buttstock: Magpul ACS Stock in FDE
Pistol Grip: Magpul MOE in FDE
Finish: Cerakote FDE (other colors available in Duracoat & Cerakote)
Magazine: Modified Magpul 10 Round Magazine with 6 Round Capacity
Weight: 9.75 pounds
Overall Length: 41 inches