Thanks to the ingenuity of one man, a Marine infantry unit serving in the Korean War was equipped with M1 Garand rifles capable of full-auto fire. This is the story of selective fire Garands built by then Marine Staff Sergeant Harold Johnson that were used in combat during the Korean War.

During the Korean War, WWII Marine combat veteran Harold Johnson, at the time a staff sergeant, was serving as platoon sergeant in 1^st Battalion, 5^th Marine Regiment. During his time there, the Korean Army was largely out of the fight, and the enemy were the Chinese communists. The war was fairly static, and his unit spent the bulk of their time in an established bunker and trench line. There were frequent Marine night patrols forward of their line to keep themselves informed of enemy troop activities. Most of the Chinese troops in his area were armed with the Soviet PPSH submachine gun. Naturally most of Hals Marines were armed with the M1 Garand or M1 Carbine with approximately one Thompson submachine gun and one Browning Automatic rifle per squad. In short, he felt that his patrols were short of firepower when they engaged in skirmishes with the Chinese during patrols.

Accordingly, Hal Johnson modified several Garands, though the total number is unknown, to be capable of selective fire. He did this work in the field, which is testimony to his skill. Also bear in mind that Hal Johnson was a tanker in WWII, and an infantryman after that; it was not until after the Korean War that he moved into the Ordnance Corps.

During our many conversations, Hal stated to me that he always sent at least two of his modified rifles out with each patrol. In use, the modified rifles provided good, reliable service. They put lots of rounds in the direction of the enemy and helped keep their heads down. On occasion the front hand guard would char or even smoke from the overheated barrel. A story Hal liked to tell was of a buddy of his from WWII arriving at his unit. This guy’s attitude was “a Springfield was good enough to shoot Japanese, its good enough to shoot Chinese.” Accordingly, he carried a Springfield on his first night patrol, made contact with the enemy and heard burp-gun fire all around him. Upon his return to friendly lines, he promptly asked Hal for one of his modified Garands.

HOW WAS THE RIFLE MODIFIED

The modification made by Johnson was simple in design and was reliable. Starting with the trigger group and working forward, the left disconnector hook is ground off of the hammer to prevent that left hook from engaging. A trip lever is fabricated and installed inside a channel cut inside the stock. This trip lever has a lug welded to its rear that protrudes into the action of the gun. This lug engages with the right side of the disconnector. This trip lever pivots on the selector switch to the rear of the center of the trip lever. A spring is installed under the rear of this trip lever to provide upward tension. A transfer bar is fabricated and installed on the outside of the stock below the charging handle. It pivots at its center and has no spring tension on it. The charging handle is ground flat on its front surface. The transfer bar and trip lever were fabricated from M1919 and M2 .50 caliber feed cover belt feed levers. Disclaimer: This is not a how-to guide on building your own full auto M1. Do not modify an M1 to fire full auto unless you are in possession of the appropriate licenses.

HOW THE RIFLE WORKS, THE CYCLE OF OPERATION

When the rifle is fired, the operating rod moves to the rear, bringing the bolt with it. At the beginning of this movement, the flat surface of the charging handle moves away from the transfer bar. Spring tension on the rear of the trip lever moves it up out of engagement with the right side of the disconnector. toward the end of the rearward travel of the bolt, the hammer will lock in the rearward position, held by the disconnector on the remaining right lug on the hammer. As the bolt is returning forward, and just as the bolt locks up, the flat cut into the front of the charging handle impacts the top of the transfer bar forcing the rear of this transfer bar up. This forces the front of the rear trip lever up, moving the rear of the trip lever down against spring tension. The lug welded to the rear of the trip lever pushes down on the right hook on the disconnector, pushing and holding it to the rear and releasing the hammer to fire the chambered round and firing the successive round. The cycle repeats as long as the trigger is held down, or until the rifle runs out of ammunition.

A MODERN REPRODUCTION OF HAL JOHNSONS DESIGN, PROOF OF CONCEPT

Some years ago, in the post-1986 era, but prior to the advent of handheld movie studios, hence the low-quality photos taken with a disposable camera, a working copy of Hals design was built. It was built under my tutelage by a tax stamp holder. That individual has long since surrendered his tax stamp and the rifle was duly turned into the BATFE. I like to think that it resides in their reference collection. It was built as a tool-room prototype with no attempt to make it pretty or field worthy. It also lacks the selective fire option and is full-auto only. This rifle ran and ran flawlessly for many rounds. The rate of fire was an estimated 600 rounds per minute. Controllability of this rifle was not great, but it was manageable for an experienced full-auto shooter. As the owner of an original M-14, I can state that it was more controllable than an M-14 in full-auto mode. It is worth noting that it is possible to build this design to operate at a rate of fire of 600 per minute up to 800 rounds per minute. To do this imagine the lock-up of the bolt and auto firing taking place during a very short window of time. If the rifle fires at the earliest moment in this window, the rate of fire will be faster. The reproduction rifle I fired could have been made to shoot at a higher RPM by adding metal to any contact surface in the linkage, causing a slightly earlier release of the hammer by the lug on the rear of the trip lever.

Though largely unknown, Garands capable of full-auto fire were used in combat in the Korean war by infantry Marines in 1/5 courtesy of the efforts of one smart and able man, Harold Johnson, who has gone largely unrecognized by history.

During 1983-1985, Harold “Hal” Johnson designed and built an experimental prototype .30 cal., lightweight machine gun for the Austin Aerospace Corporation for use on their ultra-light aircraft, the Austin Hawk, the Austin Armament Support Program (ASP) referred to it as the ASP machine gun, showing it as a twin gun system in their promotional literature. Two ASP machine guns and a supply of 1000 rounds of belted .30 caliber carbine ammunition in M-27 links formed a light-weight offensive/defensive gun system. This gun system, when mounted under a Hawk, would have been used for scout and escort missions in a hostile environment. This system never saw field use, and all that remains is one gun, some drawings, some literature, several memos, a few photos, and a rather interesting story.

Prior to tasking Johnson with the design and manufacture of the ASP machine gun, Austin Aerospace did a trial with dual-mounted 7.62 NATO caliber M-60 machine guns on their Hawk aircraft. The M-60 was available as an off-the-shelf item and was well worth trying as it had a proven track record. Two M-60s were mounted on a Hawk and, during live fire with the Hawk air born, one of the M-60s jammed and ceased firing. Due to the sudden lack of recoil impulse on one side of the aircraft, the aircraft became unstable in flight. At that point it was decided that a recoil-free machine gun was what they needed. This live fire testing was done at Edwards Air Force Base, California.

The .30 caliber carbine round was chosen because it most closely met the criteria for this weapons system: a gun and caliber combination that Austin literature states has an effective range of 600-700 meters and a maximum range of 1400 meters, and that was as near to recoil free as possible. The fact that an ASP with a given load of ammunition was approximately half the weight of an M-60 with the same quantity of ammunition was also a factor.

The gun is simple in design, and could be produced in quantity without great expense. The bolt has a fixed firing pin, with a claw extractor, and operates much as a blow back sub machine gun does. When cycling, the bolt travels to the rear, until spring tension overcomes the movement of the bolt, and pushes it forward to pick up and fire the next round.

The gas operating system is somewhat unique. Gas is tapped from the barrel, travels to the feed block in a gas tube and powers a feed piston with an attached feed pawl. High pressure gas pushes the piston and the attached feed pawl over the next linked round. As  pressure drops in the barrel, the compressed gas piston spring repositions the piston, whose feed pawl positions the next linked round in the feed block for pick-up by the forward traveling bolt. The  guns are fired by the pilot via an electric trigger motor.

The Austin Hawk was intended for sale to small countries fighting small non-conventional wars. It was small, lightweight, and modular for ease of shipping. It would be easy to maintain and easy to learn to operate. (Part of what Austin Aerospace was going to offer was training on operation, and use and maintenance of the system). It could operate off a 300 foot, smooth surface and while no information exists as to the cost of a complete system, it would certainly have been less expensive to buy and operate than modern military aviation hardware.

Johnson did not make any profit from his design and work on the ASP. There is a memo to him from Austin Aerospace explaining that he would receive a $15-per-gun royalty for the first 2000 guns sold, and $7.50-per-gun thereafter. In this he joins many inventors throughout history who did not receive a benefit for the fruits of their labor.

Sidebar: A word on Hal Johnson. Hal grew up in New York near Bannermans, and got an early start In the world of guns. He enlisted in the Marines at age 17 in 1944 and fought on Okinawa as a bow gunner in an M4-A2 Sherman tank. He served in the Korean war as a platoon Sgt in 1st Battalion, 5^th Marines. He went on to serve 20 years and retired as a Chief Warrant Officer after spending most of his career in ordnance, to include having been the officer in charge of the 5th Atomic Ordnance Platoon at Camp Pendelton. (Atomic Ordnance Platoons are now called Nuclear Ordnance Platoons). He authored several editions of the Defense Intelligence Agency’s Small Arms Identification and Operation Guide’s. Simply put he was the master of all things ordnance.