Weapons of War: The Pedersen Device—A Game Changer?

A Doughboy Aims an '03 Springfield Equipped with
the Pedersen Device

By James Patton

The U.S. Army’s standard issue M-1903 Springfield rifle in .30-06 (7.62x63mm) received a few technical innovations during World War I. The most common was the addition of optical sights, and perhaps the most unusual was the Pederson Device, a mechanism that replaced the bolt on a slightly modified M-1903 rifle designated the Mark 1, thereby converting it into a semi-automatic that fired a .30-18 (7.62 x 20mm) pistol-length cartridge fed from a detachable 40-round box-type magazine. The modification required milling an  ejection port into the receiver, which could only be done at the factory. The device itself was a complete blow-back semi-automatic pistol like the Remington 51, sans hand grip, forming a gun within a gun. This conversion dramatically increased short-range firepower, which would be useful for close-quarter fighting and hit-and-run raids. 

Soldiers could use their M-1903 Mark 1 rifles normally; then with a simple switching of the bolt, they had a semi-automatic that fired at a rate of 80 rounds per minute. This switch-over took about 15 seconds. (The five-shot .30 06 magazine didn’t even need to be unloaded.) Each soldier had  special pouches to store the bolts in and carried five loaded Pedersen magazines in another pouch. 

Comparing the Standard
'03 Round with the Pedersen Round

Critics pointed out that the 24”  barrel of the M-1903  would still be a handicap in close quarters. Indeed, all of the various weapons subsequently designed for this purpose have short barrels, like the Sten, the Uzi, or the HK MP5. Another criticism was that the magazine could be inserted backward, certainly a serious risk in heated combat.

The device was invented in 1917 by John Pedersen (1881–1951), who had been a long-time employee at Remington Arms. Before the contract was cancelled in 1919, a total of about 65,000 of his devices were made at the Rock Island Arsenal and Remington’s Bridgeport factory, along with 1.6 million of the magazines and over a million of the Mark 1 rifles with the ejection port. The U.S. government paid Pedersen a flat fee for the rights plus a per-unit royalty; he earned over $85,000 (about $1.8 million today). 

John Pedersen Holding an Adapted '03
(Without Magazine) and His Device (Left Hand)

No Pedersen Devices were ever issued to soldiers. Instead they all wound up in storage until 1931, when the government ordered them destroyed, probably to keep them away from criminals, although those folks  already had a lot of the .45 ACP Thompson sub-machine guns, which were sold without restriction from 1921 to 1934. Most of the Pedersen Devices were melted down, but some were evidently pilfered. Allegedly, the ones stored at San Antonio, Texas, were supplied to reinforce concrete in local sidewalks. 

Today only a few Pedersen Devices survive in private collections and museums, some of them showing signs of attempted destruction. Pedersen also designed similar bolts for both the U.S. produced M-1917 Enfield and the M-1916 Mosin-Nagant rifles, which in order to be used would also have required the Mark 1 ejection port modification to the rifles. Reportedly prototypes of these two devices were handcrafted by Remington but neither went into production. For those curious, this video demonstrates how to modify your Springfield for  the Pedersen Device:

Later, Pedersen designed a complete semi-automatic rifle, officially called the T1E3, but widely known as the Pedersen Rifle, which lost the competition to the Garand Rifle in 1932. Pedersen also designed a .276 (7 x 51mm) cartridge for the Army that testing demonstrated was superior to the .30-06, but the Chief of Staff at that time, Gen. Douglas MacArthur, quashed the program. He cited logistic constraints: (a) unnecessary cost—the army had huge stores of paid-for.30-06 ammo to use up and (b) complexity of supply chains—all of the machine guns and automatic rifles would still require the .30-06 ammo. It is also said that he personally regarded the 7mm bullet as  too small. 

During WWII Pedersen was a principal in the Irwin-Pedersen Arms Co., which was the original manufacturer of the M-1 Carbine (7.62 x 33mm), which wasn’t a Pedersen design. Although both the carbine and the Garand Rifle were badged as M-1s, they share only one non-essential part and they don’t use the same ammunition.  Most of the carbines were made by the Saginaw Gear Division of General Motors and were still in use in special circumstances up through the  early days of the Vietnam War. 

Pedersen Examining a Competitor's Garand Rifle,
Prototype of the M-1

The Soviet SKS semi-automatic rifle (7.62 x 39mm), introduced in 1949, bears a striking resemblance to the Pedersen Rifle, although the two are mechanically dissimilar. Pedersen also designed many shotguns and rifles  for Remington, mostly using pump actions. He was granted 69 patents in his lifetime. 

Sources include The American Rifleman, The Armory Life and The Rock Island Auction Co.

Here is a LINK to a more detailed article about the Pedersen device.