Featured MicroMOA’s ‘Govnah’ Adjustable Gas Block (Pt 1 of 2) David Merrill January 27, 2014 0 COMMENT Whether on the job, at the range, hunting, competing or otherwise, we all want our guns to run optimally. Anything we can do to decrease parts wear and increase controllability without sacrificing reliability is beneficial. Many factors come into play when we talk about optimal cycling of an AR/M16. One has to strike a balance between barrel length, gas system length, gas port size, extraction force, buffer weight, recoil spring length/strength and more. Thankfully, most manufacturers take care of the bulk of that for us. However, through the last… oh say 50+ years, many changes have taken place. A recent development is the MicroMOA Govnah, a modular, multi-setting, low-profile, quick adjustable gas block for AR15, M16 and M4 platforms. I will be reviewing this “Govnah.” First Though, Some Background Remember that this was rifle originally designed as a 20in barreled 7.62N rifle and then later adapted to 5.56mm. As time went on, barrels got shorter and new challenges presented themselves. Gas systems had to be redesigned, which caused new extraction issues that had to be addressed. Adjustable stocks were implemented which meant a redesign of the action spring assembly and new buffer size/weights had to be accommodated. The closer the muzzle comes to the gas system, the less the dwell time. Gas port size had to be enlarged to compensate for this and the pressure the extractor has to deal with during cycling increased—basically, the shorter that a system gets the more engineering problems that had to be overcome. None of this is to say that there is something inherently wrong with the AR system—far from it; just that times have changed a bit from when it was initially designed in 1950’s to today. For some reason there is always a contingent of people that view any change to a system as egg on the face of the initial design instead of what of the rest of us call it: adaptation to new missions, tactics, and battlefields (in short: ‘progress’). ‘If it doesn’t eat cheap Russian Ammo then I don’t want it!’ Since the original design and subsequent changes were made with the military in mind, AR-15s were made to run with NATO-spec rounds. However, the civilian market has access to a wide variety of ammunition, much of it comprised of wildly divergent materials combined with relatively dubious quality control. It wasn’t long before many companies opened up gas ports to accommodate the use of an expanding assortment of ammunition (sometimes even while outright stating that using non-spec ammunition would void any warranty). It is the, ‘If it doesn’t eat cheap Russian Ammo then I don’t want it!’ mentality that has caused most of the commercially available AR-15’s on the market to be largely over-gassed. No, I’m not directly bagging on inexpensive (well, has anything really been that inexpensive over the passed year?) ammunition; even though much of it leaves something to be desired in the accuracy department it has a good place in short/medium range training. However, they hand over less pressure when fired and therefore do not function reliably in systems designed for full-power rounds. As such, gas port size was increased. In and of itself, this isn’t always a problem; I have a good friend who has a carbine he consciously set up to solely live on a steady diet of low-pressure steel cased ammunition. When you have a rifle that gleefully chows down an ample assortment of ammunition you can begin to run into gas problems when using NATO-spec loadings. Too much gas can cause: Failures to Extract (FTE) Failures to Feed (FTF) From too high of a bolt carrier speed or seemingly paradoxically, from short-stroking (caused by attempted early extraction and subsequent stuttering of the BCG) Increased Recoil Decreased Parts Life Increased Fouling Higher Frequency of Lubrication There are countless products that exist to address these issues, some practical and others gimmicky. There are numerous buffer weights and action springs available to retard the speed of the bolt. Extra power extractors, wonder lubricants, extra large diameter gas tubes, long twisty gas tubes, lighter BCG’s, heavier BCG’s and the list goes on and on. The usual advice is to run the heaviest buffer and action spring configuration that your rifle allows for a given loading. In this way, bolt speed can be managed and the rifle runs smoother and more reliably. Often times this leads to a juggling of buffers and other components when switching loads. Now, at this point you may be asking yourself, ‘Is my rifle over-gassed?’ While there are a bunch of pictures and charts talking about ejection patterns etc here’s a really easy way to tell: If you can run imported steel-cased ammo without any special modifications, your rifle is over gassed when using quality brass. Even if you have a rifle with a small gas port, it will enlarge given enough use. Gas port erosion was once considered a, ‘self-correcting’ problem because some carbon builds up over the eroded areas. However, the difference in the cycling of a brand new carbine and a well used one of the same make/model is noticeable. Select-fire, suppressed, and short barreled rifles will suffer gas port erosion faster as well as barrels that aren’t chrome-lined or of inferior metallurgy. Enlarged gas ports on commercial carbines and gas port erosion aren’t the only cause of increased gas though. Adding a suppressor to a gun vastly increases the amount of gas coming through the system. Gas back-pressure increases when a suppressor is attached because a suppressor works by containing the expansive gas explosion that happens when a projectile leaves the muzzle. The gas, once introduced back into the receiver, acts like an enlarged gas port on steroids. Gas escapes from everyplace it can and the evidence can easily be observed around the seams of a rifle which has been amply fired while suppressed. The same fixes apply though; heavier buffers, stronger springs et cetera. There are other fixes as well, some more permanent than others. Gas adjustment has existed in one form or another ever since gas-operated firearms were developed. Some require special wrenches while others have set screws and others switches and dials. The ability to quickly change the gas setting, especially when employing a suppressor, is a boon. Instead of switching buffers and springs all one has to do is flip the appropriate switch or turn a dial. That brings us to our current subject. The MicroMOA ‘Govnah’ Adjustable Gas Block. The Govnah is a multi-setting, low-profile, quick adjustable gas block. Though aesthetics rarely matter to me (especially on a part that is going to be hidden by a rifle forend) the Govnah is visibly appealing. Both the gas block body and the regulator plates are tooled out of 416 stainless steel and then Blacknitrided for a smooth and uniform finish. When doing the first visual inspection I noticed the Govnah was low-profile but slightly longer than initially expected. This is due to the spring/detent system used to hold the regulator plate in place. The height is 1.38” and width is 1.38” or 1.22” (3-position or 2-position regulator plate fully extended, respectively). Currently the only barrel diameter available for the Govnah is .750”, with a .625” version currently in the works. The gas block easily fit under my forend system (Noveske NSR) and allowed free-float with no problems. They can also be installed under many other small diameter forends such as the Troy TRX/Alpha. In order to get at the adjustment of the Govnah, there has to be some sort of access port. Most free-floating handguard and rail systems have holes or slots for heat dissipation purposes and usually provide a suitable channel. If you can see your gas block through your current forend you can probably use the Govnah, though you can contact MicroMOA for questions about specific compatibility. The Govnah is available in with several standard suppressed/unsuppressed 2-port configurations (12” barreled carbine, 16” barreled carbine, and 16” mid-length). Each Govnah in one of the standard 2-port configuration ships with two different regulator plates: One for milspec ammo and one labeled, ‘Extra gas’ (IE: For lower-powered imported stuff). There is also an option for a set of customizable 2 or 3-port regulator plates. Unlike the 2-port plates, there are no set standard port sizes for the 3-port regulators. The custom 2-port plates come with 1 pilot hole drilled and one center drilled ‘starter’ hole. The custom 3-port plates come with 2 pilot holes drilled (one on either size) and one center drilled, ‘starter’ hole in the middle. More on how to determine custom gas port sizes later in the article, after we cover installation, regulator plate exchanging, gas port selection-test-tune and lots of conclusions. Come back tomorrow to read Part 2. About the author: An experienced Marine combat veteran, Dave Merrill was formerly an urban warfare and foreign weapons instructor for Coalition fighting men. Dave is currently an instructor and operating manager for MilCopp Tactical. MilCopp teaches and advocates a constantly evolving amalgamated method of military and law enforcement tactics. These TTPs are based on a combination of hard lessons learned and practical real-world results. 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