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Posted: 2/6/2014 2:41:35 PM EDT
| I'm taking the leap into the AR-15 world pretty soon with the purchase of an S&W M&P 15 Sport (don't try to talk me out of it, I'm sure), and one of my biggest concerns is that I will applying a can as soon as possible because of where I live. I just don't want to make too much noise for the people around. So my issue is with the back pressures associated with suppression, will all that gas bang up my rifle? I'm really considering one of the JP adjustable blocks, because I know they make the shooting a lot smoother, but will the standard gas system cause any DAMAGE? |
| No, it won't cause any damage. It will increase wear though, and accelerate it. Your gas rings will go out faster than normal and you're going to have to lubricate/clean a little more often. I run a Daniel Defense with a carbine length gas tube, H1 buffer, and it has ran like a top. Not one malfunction or issue. You will experience a bit of gas to the face and there are numerous work arounds for it. If you would like, you still can invest in the adjustable gas block, as it really can't hurt. |
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When you add a suppressor, you have created an imbalance in that firearm's gas system. You now have too much gas/backpressure. This will increase recoil, parts wear and gas in face/fouling. Many will say just throw a heavy buffer at it. The heavy buffer will help reduce the recoil but won't do anything in reducing the amount of gas now coming from the gas tube. Adding a heavy buffer just addresses the symptoms and not the problem which is too much gas. Heavy buffers also add unnecessary reciprocating mass. Why do that when it worked fine with a lighter buffer to begin with? I do all my full auto testing with an H2 buffer. H2 buffer is all you need to kill bolt/carrier bounce in full auto. If not running full auto, H buffer is fine if controlling the gas. IMHO, controlling the gas is the best thing to do. There are several products out there to address this. Many set screw adjustable gas blocks out there but they all require an allen wrench to adjust it. If you are fine with that, then that may be what you need. When it comes to 'tool less' options, there are much less to choose from. My tool less (and now recently patented) gas block is the ONLY tool-less adjustable gas 'method' that uses a standard UN-Modified gas tube that is currently available. It is modular in the sense that the regulator plates can be swapped out for a 2 or 3 position to handle any length gas system or caliber. Use a bullet or other small object to push the regulator plate to the desired position. In addition, with the modular plate design, you have the flexibility to configure it in several different ways. All of the tool less options out there that have pre set positions give you suppressed and just full gas but the fact is that pretty much every barrel out there is over gassed since barrel manufacturers have to make barrels that will function with the cheaper surplus ammo out there. So with my design you can have an optimal suppressed, optimal un-suppressed and an 'adverse' position which basically matches your barrels gas port. So if you are running suppressed in the optimal suppressed mode and you gun gets dirty you can always go to the optimal un-suppressed to keep your gun running and then go to adverse for even more gas if necessary. While regulating the gas in not 'necessary'. There will be increased recoil and parts wear and it WILL be NECESSARY to clean your gun sooner if you don't regulate it. Below is a video taking at high speed (480FPS) showing the difference between regulated and unregulated. Both are shot at the same 480 FPS and the first shot is at the same time. Both videos are the exact same gun, fired in full auto 10 rounds, M855, H2 buffers in BOTH. Only difference is the one in the lower right is regulated. There was so much gas coming out of the unregulated that it fouled up the glass in front of the camera. If you look closely, you can also see more recoil on the unregulated. I could feel the buffer bottoming out. VS the regulated, you can barely make out any gas coming out of the ejection port and 3 rounds are fired after the unregulated has finished its 10 rounds since it is about 200 RPM slower when regulated vs unregulated.  Below is a demo video using a Silencerco Saker and 10.5" barrel: Here is another video I did recently showing that even after heavy suppressed full auto fire, that the regulator can still be easily moved and does not get stuck. Below are some links to a new two part article that came out this week on the MicroMOA Govnah that covers the background and Govnah solution and testing quite well - all with RoF informatioin. Part1 http://www.recoilweb.com/micromoas-govnah-adjustable-gas-block-38489.html Part 2 http://www.recoilweb.com/micromoas-govnah-adjustable-gas-block-pt-2-of-2-38639.html   I've got plenty of pics/videos/info on my site: http://micromoa.com Let me know if you have any questions. |
| It's not that my mind is closed for other gas systems, but my mind is closed to other complete rifles. I've thought about building from scratch and done so much research, but I think after all that it will be good to start complete to learn what I want out of my rifle. This will be my first rifle but I've shot plenty of friends' ARs before and the M&P Sport is just too much value for the money. Thanks to everyone for the input. That non-tool adjustable gas block looks ideal, and I would like to prevent wear where possible (I'm a pretty heavy shooter). I've looked into other adjustable blocks and thought I could chop up an Allen key to fashion a convenient little key of sorts to adjust the gas on-site, but the adjustable plates look great too. I suppose it might depend on the price point. I am a poor college student, unfortunately, and getting hold of the suppressor brought up some scary numbers, heheh. |
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Options:
Buy 16" carbine. Buy suppressor. Have a knowledgeable AR smith Cut down 16" to 10.3 - 11.5". Have a knowledgable smith open the gas port to just cycle (barely) unsuppressed with regular buffer.. The 16" carbine will have a pretty small gas port. You will be much less overgassed suppressed then. Other option: keep the barrel, but have the smith weld up and re-drill (smaller) the gas hole to again, just flop cases out unsuppressed with regular buffer. |
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Another option is our 'baby Govnah' pictured below: It is only $20..... It has a small .043 port and is countersunk a little to allow for some misalignment since it doesn't have an alignment hole like the regular adjustable Govnah. .043 is the smallest I've seen any configuration cycle suppressed. You need bigger? Just drill it out till it works for you. I would recommend a numbered drill bit set (NOT fractional as it is not granular enough). For a dedicated suppressed 556 shooting decent ammo, I'd suggest .046. If shooting crap ammo then bump it to .049 which is a 1.25mm bit.  |
| Thanks for the advice deadwormer. I see where you're coming from and I see how that would work, I'm just definitely not willing to cut the barrel (except for the thread job) and my upper won't be truly dedicated to suppressed use. There will be times the noise level won't matter, like on shooting trips. At the price, that baby govnah' sounds like a sweet deal. So it's almost the same as the govnah, save the alignment hole? |
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Quoted: At the price, that baby govnah' sounds like a sweet deal. So it's almost the same as the govnah, save the alignment hole? It's just a lo profile gas block but instead of making the standard 10-32 tap drill hole for the gas port, we drilled a .043" port and it's countersunk. The baby Govnah is a simple cost effective solution to correct overgassed barrels. You just drill it out to what you need and that is it. There is no real adjustability. The regular Govnah is quite a bit different which is a patented, tool less, modular adjustable gas block and currently the only tool less option on the market today that uses an unmodified standard gas tube. Plenty of detail on it in the article I mentioned in my post above as well videos and more data at my site: micromoa.com If you really want to 'cheap out' then just get baby Govnah and a spare gas tube and roll pin and leave them together. Swap out the entire, block and tube when you want to shoot suppressed and have another gas block/tube assembly which is wide open for un-suppressed usage. |
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New to all this, can due in a month.
I will be suppressing a stag carbine, probably a midlength gas system. This is my only ar with a removable flash hider so it will probably be the only one I run suppressed. Should I try it out first then investigate rehabbing the gas system? Thanks |
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Quoted: New to all this, can due in a month. I will be suppressing a stag carbine, probably a midlength gas system. This is my only ar with a removable flash hider so it will probably be the only one I run suppressed. Should I try it out first then investigate rehabbing the gas system? Thanks Everyone is different. Some people don't mind the gas in the face. Some people don't care if their gun has increased recoil or that it is getting fouled so much faster and don't mind having to clean their gun sooner. It also comes down to how much you shoot and how reliable you want this configuration to be without cleaning. If you don't mind all the negatives and this is just a range toy that isn't run hard then maybe you just leave it the way it is. On the other hand, if you do want to address all the issues mentioned, I highly recommend that you choose the option of controlling the gas whether it be my product or any other gas regulation method since that addresses the source of the problem not the symptoms of the problem....like the special parts that deflect excess gas or specialty buffers. Feel free to contact me if you have any questions. |
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