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M11/9 Rate of Fire Adjusters for Competition and Recreational Shooting!

By Keith Barlow

The SWD M11/9 is a little pocket rocket with a lot of potential. Being the most widely produced machine gun in the National Firearms Act (NFA) registry, M11/9 parts are a rapidly growing cottage industry, just like for the venerable 1911. Prior to the last couple of years, the M11/9 had been viewed as a bullet hose with little value other than burning ammo and having a “good ol’ time”. As prices continue to rise on transferable machine guns (the price of the M11/9 has more than doubled in the last two years), enterprising individuals have developed many accessories to dress up the M11/9, the last “cheap” machine gun. The M11/9 has been winning more and more subgun competitions, land that was once dominated by the HK MP5 and M16/9. One of the newest cottages in this market is the rate adjuster. I tested rate adjusters from TASK, AutoWerkes, Garrison Precision, Tactical Innovations, and Urbach. Since each of these units has been, or will be shortly, the subject of its own article, the purpose of this article is simply to compare the performance of them all in one place. For testing, I used the same M11/9 on all adjusters except the TASK. The lower has Tactical Innovations’ Sten conversion. All testing was done with S&B 115gr fmj ammo from Discount Distributors, all fired from the same magazine to account for any variances in rates of feed. Rates of fire are shown in Table 1.

The first commercial attempt at a rate reducer was the Urbach Slow Fire bolt. This bolt, built by Murray Urbach, is made heavier than the standard bolt by shrinking the ejection port substantially, utilizing a fixed firing pin, squared rear end, and tighter barrel slot. It does not achieve the low rates of the other slow fire conversions, but is more affordable than most. I was able to achieve 2 round bursts reliably with the Urbach bolt. It is $175 complete with recoil assembly.

The first M11/9 rate adjuster to challenge the MP5 and M16/9 was designed by Matt “Mongo” Bright and Jim Weaver. It is accomplished by making the bolt heavier, but not by adding mass to the bolt itself. Their method, commonly referred to by their shooting association acronym “TASK” (Triad Action Shooting Klub), removes the factory recoil system from the bolt, replacing it with a rod that extends through the rear plate of the receiver (requiring a hole drilled in the receiver), to actuate an M16-type buffer, mounted in a M16 stock. There are quite a few buffers to choose from, including the factory M16 buffer, the Colt Hydraulic buffer, the segmented AAC Rate Reducer buffer, and the Teflon jacketed buffer from Matt Bright. Rates achievable from this system vary depending on the buffer used and the stock (A1, A2, or CAR) used. The CAR-stocked gun does not get as low as the others because of the shortened recoil stroke. The Teflon buffer is available from Matt Bright for $50 and your buffer. It functions by stopping airflow around the buffer, causing an increasing resistance behind the buffer. Having the TASK conversion done on your gun runs $900, and includes a new upper with 10” compensated barrel, MP5K style K-grip, scope rail with Tasco Pro Point mounted, Wheatley Sten Mag conversion, reparkerizing, and of course, the slow fire conversion of your lower and bolt. The TASK conversion allows very easy single shot trigger pulls, with very little practice. You can also do it yourself, with a little elbow grease and know-how. Bill Ehringer’s step-by-step instructions can be found at

Garrison Precision Machine, LLC has recently introduced a noninvasive rate reducer in the patent-pending VSF upper. The idea here involves adding weight to the bolt by attaching a rod to another weight in a separate enclosure on top of the upper. It is as unconventional in appearance as the TASK conversion. It has the added benefit of raising the sight line to allow a better cheek weld on the stock. It is available with standard barrel or 10” barrel with K-grip. Both styles come with a scope rail mounted on top and the charging handle relocated to the left side of the upper. The VSF also allows use of any stock of your choice, or no stock at all. There is no modification to the lower, so you can compete with the same lower in different classes with nothing more than a quick upper change. The VSF equaled the performance of the TASK, allowing simple one shot bursts, if you can call one shot a burst. MSRP is between $425 and $495 depending on configuration.

Another rate adjuster is the AutoWerkes Drop In Rate Reducer (AW DIRR). This unit mounts below the bolt in the rear of the receiver and adds weight to the bolt from behind. The patent-pending AW DIRR has a spring-mounted lever that acts on the bolt as it recoils, there-by slowing it down. Its advantage over the TASK is there is no modification to the receiver, and the advantage on both the TASK and the Garrison on price. The AW DIRR took a little more practice to get one shot at a time off, but it is entirely possible. If you are not looking to compete, or just don’t want to spend the money on the others, this conversion will allow you to maintain the look of your M11/9, while lowering the cost of feeding the little beastie. MSRP is $175.

At this point in our story, we come to what some consider a bane, others pure joy: the rate increaser. There are several ways to accomplish this feat. The first two involve increased backpressure. The 10” barrel increases the rate somewhat by keeping pressure in the barrel longer. The same is accomplished with a sound suppressor. The third is the patent-pending Tactical Innovations Mac Jack. This is a piece of high tech plastic, which is inserted between the bolt and the rear of the receiver (just like the standard buffer), causing the bolt to short-stroke. It allows the bolt to come far enough back to engage the sear, but not much farther. Some (or most) folks will ask, “Why?” Then they shoot it, and then they want to know where to buy one. When you combine the MacJack with the 10” barrel or suppressor, you really have a screamer. Several friends of mine have told me they achieved 1800+ rpm with the Mac Jack, but their unJacked M11/9s also run 300+ rpm faster than mine. Don’t even think about one or two shot bursts. It sure is a fist full of fire-breathing fun, and for $25, it is by far the most affordable in this article.

The SWD M11/9 has really gained in popularity in the last 2 years, owing much to JLM & Sons’ buying the remaining inventory from Wayne Daniels in 1998. Approximately 1500 NIB M11/9’s went on the market in just a few months time. The M11/9 has the ability to become a real champ with just a few accessories, and with a rate adjuster, it becomes much more than a bullet hose.

Contact info:

Discount Distributors
12 Stoney Hill Lane
Mt. Laurel, NJ 08054

Urbach Precision Mfg
1529 Axe Dr.
Garland, TX 75041

Top Ends, Inc.
Jim Weaver
6935 Wildwood Tr
Thomasville, NC 27260

Garrison Precision Machine, LLC
PO Box 72665
Louisville, KY 40272-0665

AutoWerkes Mfg
87 Deer Meadow Ct.
Weldon Springs, MO 63304-7718

Tactical Innovations, Inc.
Craig Wheatley
PO Box 3
Glen Burnie, MD 21060


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