Double Your Fun, Legal and Affordable Title I Fun: The Twin MG-42/22

By William D. Ehringer

The private ownership of a machine gun is, in many cases, denied to some citizens in the United States because of where they live or the inability to acquire the all-important chief law enforcement officer’s signature that is required on a Form 4. However, while the firearms enthusiast may be relegated to owning Title I weapons, it does not necessarily imply that he or she cannot own a firearm that fires at the cyclic rate of a machine gun. In fact, many legal “gadgets” have been made in attempt to allow Title I owners the opportunity to “feel” full-auto fire. These include such devices as the “HellFire Trigger”, “Tri-Burst”, “HellStorm 2000”, and the “BMF Activator”. While it is true that these devices do allow the Title I owner to simulate the cyclic rate of a machine gun, the firing of the gun usually compromises the ability to aim the weapon at the target.

Imagine if you could use one of these trigger devices to fire a Title I weapon with the accuracy of its full-auto cousin, and achieve cyclic rates that surpassed the rate of fire of the infamous SWD M11/9 bullet hose! Now imagine if you could do this without having to fill out a Form 4, acquire a CLEO signature, or pay for a $200 tax stamp. Furthermore, imagine that such a gun was legal in all 50 States and did not cost an arm and a leg to shoot! The Twin MG-42 is just such a beast, and for under $900 you can make one for yourself.

Making a Twin MG-42:

The first thing I did was to select a firearm platform that was readily available, inexpensive to shoot, and easily modified. The Ruger 10/22 is the perfect candidate for this metamorphosis. The first part of the metamorphosis is to rid the gun of the “ugly” wood furniture and replace it with a beautiful “evil looking, black assault style stock.” I selected the MG-42 replica stock, which is available from Frank’s Center. The completed gun is a 2/3rds scale replica of the original German World War II gun, and consists of two components: A rear buttstock/receiver and a forward barrel shroud. Because the kit does not alter the number of “assault rifle features of the gun”, the use of this kit on any Ruger 10/22 (pre or post-1994 ban) is legal.

The first thing to do is to make the flimsy replica stock more rigid. This process entailed cutting a piece of 1/8” x 1” metal strap to the inside length of the front barrel shroud and connecting the two guns together. The metal strap was mounted with 8/32 machine screws (3/4” long) to the forend by utilizing the pre-drilled holes in the underside of the stock. A similar process was repeated on another MG-42 stock. On the underside of the forend, two pieces of 1/8” x 1” x 1’ metal strap were then used to connect (using the remaining 1/4” of the 8/32 machine screws that protrude from the underside of the stock) the 10/22s together at the holes nearest to the flash hider, and also at the point where the forend bolts to the Ruger 10/22 receiver. Two additional 6” pieces of strap were then cut at 45° angle on both ends, and one end was attached to one of the 8/32” machine screws. The opposite end of this strap overlapped at the point where the rearward most connecting straps joins the two guns. The finished product is two MG-42 replica guns mounted together in a very rigid manner.

I made my own spider-sight by taking a piece of 3” PVC pipe and a piece of 11/2” PVC pipe and cutting a 1/4” section from each. The two pieces were then connected together using thin steel rod (bicycle spokes work great) with a two-part epoxy. The spider sight was attached to a piece of 1/4” aluminum rod that was tapped on one end (8/32). The sight was then attached to the Twin MG-42 at the most distant connecting strap.

The next step in the metamorphosis was to link both triggers together. However, one of my desires was to have the guns fire in an asynchronous (90° out) manner. I also wanted them to be able to achieve the high cyclic rate that might be expected from a full-auto weapon. I based my design on the proven Calico 20/22 firearm which uses two Ruger 10/22s and a two-lobed cam mounted to each trigger. My modification to this design was to use the commercially available BMF Activator (Frank’s Center). The BMF Activator is threaded on both ends of the cam, allowing for either the attachment of the hand crank or the attachment of additional activators. The BMF Activator consists of three parts: A hand operated crank, a four-lobed cam housed in high impact plastic (that attaches to the Ruger 10/22’s trigger guard) and an activator bar. The obvious improvement in my design is that each revolution of the crank results in 8 shots being fired from the Twin MG-42 compared to the 4 shots by the 20/22.

To achieve the desired 90° out-of-phase firing of the two weapons, I took two BMF Activators (Activator #1 and Activator #2) and placed them flat on the workbench and turned the cam until Activator #1 had the activator bar at top dead center. Activator #2 was then turned until its activator bar was at bottom dead center. A 12” piece of 1/4” rod was then turned down 1/2” on each end so that the rod fit snug into the activators threaded hole. A 3/32” hole was then drilled through the activator and the rod, and a small cotter pin was then inserted. The other activator was drilled and fitted with a cotter pin in a similar manner. The result was two asynchronous BMF activators attached by the interconnecting rod.

The BMF Activator is supplied with two types of bolts. One is a plastic bolt while the other is a metal bolt. I attached the two activators to the Twin MG-42 by tapping the Ruger 10/22 trigger guard (8/32) and mounting the two activators to the trigger guards. Care should be taken when mounting the twin Activators to the trigger guards, as sufficient distance must be left between the Activator bar and the 10/22 trigger. Equally important is the correct alignment of the Activators, such that they are directly across from one another. Once attached to the 10/22 trigger guards, the dual Activator system should be tested to ensure reliability and ease of movement.

The final step in the process was to attach the guns to a stable platform. I chose the M2 Tripod (Sarco, Inc) because of its proven stability and moderate cost. To attach the guns to the M2 tripod, I took a piece of 3” aluminum rod and turned one end of the rod down to create a pintle that matched the pintle socket of the M2 tripod. The opposite end of the pintle was then drilled and tapped 1/2” x 2”. Recall that the Twin MG-42 was joined at the point were the two forends attach to the 10/22 receiver. A 9/16” hole was drilled through the three pieces of metal strap, and a 1/2” x 2 1/2” bolt was used to attach the Twin MG-42 to the tripod/pintle.

Firing The Twin MG-42:

My son really enjoys shooting the Twin MG-42, and can empty the two 50 round mags in around 4 seconds. I use two types of mags in the Twin MG-42: Ramline 50 round mags and Italian single-stack mags with the Ruger 10/22 adapters (Franks Center). The use of the Ramline mags is preferred by this writer, because they can be easily re-loaded using the Ramline Auto-Loader (Natchez Shooters Supply). I also installed the extended magazine releases made by Butler Creek, which really aid in removing the magazines. The Twin MG-42 will reliably function using Winchester Super-X 40gr Lubaloy rounds. However, other high velocity rounds such as CCI Mini-Mags or Federal Classic will also function in the guns. Clearly, the use of high-powered ammunition avoids the occasional jam that typically occurs if less powerful rounds are used.

The Twin MG-42 maximum cyclic rate was determined to be 1505 rpm on average. Of course the cyclic rate of this gun depends upon the operator. If one desires a slower cyclic rate, the crank is turned slower. However, one must avoid the tendency of turning the crank too fast, as this will result in misfires. The finite cyclic rate of the 10/22 is discussed in greater detail in a back issue of MGN (Volume 9 Number2). Once the operator has become familiarized with shooting the Twin MG-42, fairly decent accuracy can be achieved. As an example, I taped 50 orange colored clay pigeons to an old door (Figure 9). With two 50 round mags, I was able to shoot nearly all fifty targets from 50 yards away. The ability to aim the gun is significantly increased if one uses .22LR Tracer (Outland Sales). I load the tracer 1 in 4 and this really helps initial target acquisition.

One thing that always holds true when shooting the Twin MG-42 is that you can expect a crowd at the range. I have taken this gun to the range several times with my Colt M16A1 Carbine, and a majority of the onlookers are more interested in the Twin MG-42 than the real Title II weapon. The most frequently asked question is, “Is that a real MG-42?” or “Is that a machine gun?” The answer to both of these questions is NO. The true beauty of the Twin MG-42 is that it is not a Class III weapon, because the triggers are being actuated by a cranking mechanism and not an electric motor. The Twin MG-42 is legal in all 50 states and can be made and owned by anyone over 18 years of age.

The Cost Factor:

One of the goals of the Twin MG-42 project was to build a gun that costs less than a Title II firearm. The two Ruger 10/22s cost $270, the two MG-42 Replica Stocks cost $180, the two BMF Activators cost $40, and the M2 tripod was $250. The pintle, the linkage for the BMF Activators, the connecting straps, and the front spider sight were hand-made, and probably could be duplicated by a machinist for less than $100. Thus, for around $850 you can easily duplicate this project. This is less than the cost of owning even the cheapest Class 3 weapon (SWD M11/9) which after dealer costs and Tax Stamp will run you around $900.

The Twin MG-42 has exceeded all of my original expectations. The gun has a high cyclic rate, is fairly accurate, is cheap to shoot, and is a real crowd pleaser. The only detractor to owning a Twin MG-42 is that it takes 4 minutes to load the two 50 round magazines and 4 seconds to empty them. The one thing that the Twin MG-42 is in desperate need of is the “magazine-o-plenty”, but I hear they are really becoming scarce.


Franks Center, Inc
RR#1, Box 45
Nevada, MO 64772

Natchez Shooters Supply
P.O. Box 22247
Chattanooga, TN 37422

Sarco, Inc
323 Union Street
Stirling, NJ 07980

Outland Sales and Service, Inc.
P.O. Box 1082
Brunswick, Georgia 31521-1082
1-770- 924-2278

This article first appeared in Small Arms Review V1N12 (September 1998)
and was posted online on January 20, 2017


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