AR-15 Suppressor

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22BR

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Starting on the path of adding suppressors to my rifles. Since my AR already has a threaded barrel it seemed logical to begin with it. However, it does not have an adjustable gas block and I have not made any alterations to it (PSA build - 5.56 / 1x7) - will a suppressor require significant adjustments in the gas flow to work properly?

Educate me on the basics of AR suppressor operation as I am completely ignorant in this area. An AR-10 (7.62) is planned after the AR-15.

Thanks for your help.
 
MachIV shooter here makes a great 5.56 suppressor , they are optimized for supersonic ammo as sub sonic 5.56 is pretty useless being like a subsonic .22LR and almost impossible to get to cycle on a normal AR that can also be used for supersonic ammo. Thats the bad part BUT the the good news is his welded little 5x5 suppressor , with his muzzle brake in the blast chamber , is pretty hearing safe . A two position gas block is probably the handiest , as a common screw type one needs to be marked and are usually hard to see which position it is in.
https://www.eccomachine.net/product/five-by-five/
Arguement about any "hearing safe " supersonic centerfires but on my 10.5" Noveske 5.56 Ecco Machine His 6" Aquilae (.30 bore) seems pretty quiet out side ; similar to a .22 HV Long Rifle in a 16" barreled
Ruger 10-22 maybe you'd want hearing plugs for many shots. Indoors all the concussive ugliness is gone, like a .22LR Hi speed pistol .
If you want REAL quiet , and very reliable short barreled (with no adjustable block needed) true subsonic heavy 200 grain + game killing capability; I highly reccomend a .30 can and a .300 Blackout host. Very little suppression is lost by a 5.56 mm with a .30 bore !!! My son keeps the .30 Aquilae on his (family Trust) 5.56mm Home defense pistol so if he has to fire it indoors he won't be deafened. He just killed a huge deer on the property , almost silently , with his 8" .300 BO with a 220 grain bullet at 1000 fps at 53 yards . Just our experience with the good Ecco Machine products !
 
22BR said:
will a suppressor require significant adjustments in the gas flow to work properly?
Click to expand...
Depends on the suppressor my 30 caliber Gemtech ONE doesn't over gas my 16" 5.56 or 20" 224 Valkyrie and my 10.5" 300 Blackout will run fine with supers and subs.
My Optimus Micro produces more backpressure and I ba e a bootleg BCG that's adjustable on my 12.5" 5.56 I like them better than an adjustable gas block as it vents the excess gas out the port away from a right handed shooter. I wouldn't reccomend one if your lefty.
AR10s are just way gassier neither my 6 Creed or 308 would run right suppressed and unsuppressed without adjusting the gas block when using the Gemtech. My fix for that was buying 2 5th gen OSS cans when they were on clearance after the change in ownership and the introduction of the gen 6s. They're now called Huxwrx if you're planning on running both 308 and 5.56 an easy answer would be a 30 cal Huxwrx with 2 QD muzzle devices.
 
I went the 5.56 specific route when I bought mine and have come to find, it was a mistake. I should have gone with a .30 caliber can instead. A lot more bang for your buck with just one tax stamp.

I have an AAC M4-2000 which is 5.56 caliber specific. It has a quick detach type mount and works well, and I can shoot it for a bit without wearing hearing protection without any problem. Theres basically no muzzle blast, but you still get the sonic crack downrange, and theres nothing you can do about that.

When you look into the baffle stack, its pretty amazing how well it actually works, as its really not all that big, and the flash suppressor mount takes up the first half of it.

To give you an idea as to how well it works, my ears are shot (double hearing aids) and I cant shoot a 22lr from a rifle without protection, or Im about deaf for a couple of days after. I can shoot one of my AR's from my semi enclosed carport shooting 5.56 using the suppressor, without protection, and it doesnt bother me at all.

That said, I still normally wear hearing protection when I shoot with it, as if Im shooting a lot (anything beyond 50 rounds or so), my ears will start to ache and deaden a bit, especially after.

Where I found I screwed up was, my son picked up an AR in 300 BO, and bought basically the same suppressor I have, but rated for full power 7.62x51. His uses the same flash hider type ratchet mount as mine, and will mount right up on my guns. The suppressor is just a tad bigger, but its also noticeably quieter than mine when shooting 5.56 through it. Subsonic 300BO out of it is almost movie quiet.

A lot has changed too since I bought mine about a decade or so ago. There are a lot more choices and some are multicaliber from what Ive seen. If youre just going to get one though, Id consider at least looking into going up in caliber for the versatility.
 
Google - "Hodgdon SUBSONIC RIFLE LOAD DATA" .
Hornady has some info also. https://www.hornady.com/support/superformance-in-gas-operated-firearms

Don't own any suppressed. Seen many at 1500 member club. First, they are not quiet, even a 22lr pistol, with special ammo is easly heard. Autos in 223/5.56 can coat the ejected brass with soot.

Needed- A locked breach, that doesn't open when firing, helps contain noise. Sub ammo.

Seen a suppressor make out of PVC pipe, on a 223 bolt, worked ok.

The American Rifleman just compared the noise. Still need good ear protection. Hunting Loads. https://www.americanrifleman.org/content/nosler-enhances-its-legacy-quietly/
20221224_091710.jpg

I am sure there is an expert, somewhere, that has it figured out. But not at my club.
 
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In 5.56 I use the Gemtech HALO. I used them extensively in the mil on M4's with varying barrel lengths and without any adjustable gas blocks. They don't require a proprietary MB or FH- they attach right to a standard mil type A1 or A2 bird cage FH but the FH can NOT be installed with the bevel crush washers some companies sell or install on rifles and uppers. I have used them with standard gas blocks with no issues whatsoever, though you may have to use one of the H series buffers- much cheaper and easier than dealing with an adjustable gas block. AR10 rifles tend to be more finicky when it comes to this, though.
 
I think the only AR I own with an adjustable gas block is my 3gun rifle and that’s one I have never had a can on.

So, that would put me into the “try it first” camp. There is nothing to fix if you don’t have a problem.

My non adjustable bas block equipped AR’s, that run fine suppressed, range from 10.5-20 inches in 5.56. Down to 8.5” with the 300 blk and as long as 26” with the 6.5 gren.
 
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Lots of good information - thank you. It sounds like some trial and error work so I expect to be asking more questions. I am planning to start with a .30 caliber can with the hope of it being usable on more than one gun.

The AR’s were my first thought since they are already threaded but I have bolt guns in sub-.30 calibers that I am planning to have threaded as well. Does a Howa bolt .223 require any modifications or is it a matter of add the suppressor and go shoot it (obviously checking ‘zero’)?

A secondary plan is to assemble an AR-9 which is a ‘blowback’ action - would it require a buffer change to alternate between suppressed and unsuppressed operation?

Thanks again for sharing your knowledge.
 
You don't necessarily need an adjustable gas system to run a can on your AR. If your AR has issues it is one off several things to do to remedy the issue. But that's a big "IF". The rifle running fine with the can is the norm, unless you are using an odd ball setup.

Suppressors do push a lot more fouling out if the chamber during firing. You'll find that they get significantly dirtier than when firing without. My current duty gun has a Huxwrx (HIGHLY recommend) flow through can and it still gets pretty dirty. Less than traditional cans, but still more than regular.

When you get into AR 9mm guns there is no set answer. There is no standard for 9mm ARs so every one is different. What you need, or don't need to do so be dependent on which exact 9mm AR you buy.
 
Don't get real hung up on Db #s 3-5 Db doesn't make a huge difference.
To give you an analogy think of it this way look at the NRR ratings on ear protection, hardly anyone looks at them, they use what's comfortable.
A suppressor just adds another layer of reduction.
EG. My 12.5 SBR 5.56 is uncomfortable to shoot unsuppressed without double ear pro but not painful with just plugs for just a few rounds like in a hunting scenario.
Even with the short 9mm can I use, it's not painful to shoot a few rounds but you want plugs to make it comfortable.
 
243winxb said:
Seen firing out of battery, online. A dirty chamber from a suppressor may make more problens? Don't know. https://www.thehighroad.org/index.php?threads/ar9-virgin-assembly-ka-boom.844227/

Parts fitting problem?
Click to expand...
I dont have an adjustable gas block on any of my guns. Some of them are better than others, but all are definitely over gassed, and you can feel it as you shoot, both in the face with some gas (a little Permatex on the charging handle helps there), and how the gun is running a little harder. The brass leaving the gun without the suppressor goes to basically 4:00, where it goes to 2:00 or so with it on the gun.

I did have my one gun give me a couple of 3-4 round bursts while using Winchester primers. The gun was fine without the suppressor on it, but once it was on, the fun started. I was thinking it was those primers and the added force of cycling with the suppressor on the gun that was causing it to slamfire. If it was, it must have been doing so with the bolt almost fully closed, as the necks on the brass were not blown out at all.

I normally only use CCI primers with my reloads in my auto rifles and only used the Winchesters at the time, as they were all I could get. I stopped using them, and have never had any problems with the CCI's, so Im assuming the Winchesters were just a tad too sensitive.


Theres no doubt the gas is heavier in the chamber area with the suppressor on there. The brass is usually pretty sooty, but Ive never had any issues with the gun having troubles cycling because of it. Suppressor or not, I clean the gun well after every outing too.
 
The shorter the gas system, the more fickle they'll be, and the more you'll benefit from adjustment in terms of gas to the face and port noise.

As for ddicated 5.56 cans vs .30 cans, the 5.56 can match the muzzle end performance in a bit small package, but obviously you don't have the flexibility. Where the waters get muddier is shooter's ear sound levels, and in this case, a .30 suppressor will often be the better choice if you do not want to mess with gas adjustment. That is especially true of pistol and carbine length gas systems. Our Five By Five is a pretty low backpressure can, and it's actually bored as a 6.5mm suppressor would be. We've yet to find a 5.56 host that had any reliability issues with it. But we often recommend our shorter .30 cal Aquilae and Valkyrie models when people don't want to adjust gas, the larger bore further reducing the backpressure, at the expense of needing a bit more length to match the muzzle end suppression.

I do need to get more videos done, we deleted our YouTube account because they're not gun friendly, but here's a couple. The AR is a gas adjusted 10.5" firing M193

https://juxxi.com/video/48418/ecco-machine-five-by-five?channelName=ECCOMachine

https://juxxi.com/video/48419/ecco-machine-five-by-five-flash-suppression?channelName=ECCOMachine
 
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Fishbed77 said:
Not true.
Click to expand...

I do know that Port Pressure is important when it comes to working the action. The size & location of the port is not the same on all ARs.

An adjustable gas block may be usefull, when making modifications.
My factory Colt M16A1 carbine run perfectly, unsuppressed with the 5.56/223 ammo & reloads, as it was designed to do.
 
I would spend some time at Pew Science before plopping down any money on an unknown suppressor. Don't trust the manufacturer ratings.

A good suppressor that has very little back flow is the OSS line of suppressors, like this one. Free tax stamp at the moment. I have one coming.
https://www.silencershop.com/oss-hxqd-762-ti.html

Pew Science tests back pressure on their newer reviews and lists the values that will affect semi-auto functions.
https://pewscience.com/sound-signature-reviews-free/sss-6-41-oss-hx-qd-762-savage-308
 
valnar said:
I would spend some time at Pew Science before plopping down any money on an unknown suppressor. Don't trust the manufacturer ratings.
Click to expand...

Jay compiles accurate and useful data, but I would caution against making a decision based only on the composite "score", which he assigns using a proprietary formula.

If you're going to use PEW data to make a decision, one needs to first learn what the data means to them, their specific use case. If you're running a .308 AR, the cans which score the highest in his tests on bolt action hosts are likely not the best choice.

Conversely, one of the highest scoring 9mm cans in a semi-auto carbine test achieved that score because it had the lowest port noise, but it also had one of the highest muzzle end signatures, so is among the worst options for something with a manual action, like a .38/.357 lever action.

It's also extremely difficult to make a good choice based on data if you've never been able to compare some suppressors in the real world and thus interpret what those numbers mean to your ears. Some suppressors that meter really well have a particular sound or pitch that is offensive even at lower pressure (intensity, dB), while others that meter higher have a "boomy" sound that, while a higher dB level, propagates and projects differently, doesn't hammer your human ears so hard.
 
Ehh, it's not like anybody can compare silencers easily at a gun store. Besides, Jay does write all those things you mentioned on his site, in reviews and articles. All one has to do is read. I never suggested that you take the composite score and that's it.

The point stands if you are going to buy a suppressor, sight unseen, with no data, and wait almost a year, it's not a wise choice to buy something without data. No offense to the suggestions in this thread, but buyer beware even if you have scientific and anecdotal data. Had I not researched a lot, I would have chosen the wrong suppressor for my Vz.58. I don't have an adjustable gas-block on it, so the HQ-XD I mentioned is ideal for me.
 
I do know that Port Pressure is important when it comes to working the action. The size & location of the port is not the same on all ARs.

An adjustable gas block may be usefull, when making modifications.
My factory Colt M16A1 carbine run perfectly, unsuppressed with the 5.56/223 ammo & reloads, as it was designed to do.
Click to expand...

“Needed” and and “Useful” are two entirely different statements.

In fact, an adjustable gas block is completely unnecessary on many (if not most) AR-15 setups. 5.56x45mm produces far less gas than something like 7.62x51mm, where an adjustable block is actually useful.

I can vouch from experience that a fixed gas block works perfectly fine with a Sandman-S on my 14.5” and 16” mid length BCMs and 10.5” pistol. A 30-caliber can means there is little back pressure and a gas-busting BCM charging handle means no gas to the face.

I’d go so far as to say, except in the case of some exceptional (and questionable) builds, an adjustable gas block on a 5.56x45mm AR-15 is a more complicated solution looking for a problem. Which is why when the military issues cans with DI ARs (think URGI), they never, to my knowledge, have adjustable gas blocks.
 
Fishbed77 said:
“Needed” and and “Useful” are two entirely different statements.

In fact, an adjustable gas block is completely unnecessary on many (if not most) AR-15 setups. 5.56x45mm produces far less gas than something like 7.62x51mm, where an adjustable block is actually useful.

I can vouch from experience that a fixed gas block works perfectly fine with a Sandman-S on my 14.5” and 16” mid length BCMs and 10.5” pistol. A 30-caliber can means there is little back pressure and a gas-busting BCM charging handle means no gas to the face.

I’d go so far as to say, except in the case of some exceptional (and questionable) builds, an adjustable gas block on a 5.56x45mm AR-15 is a more complicated solution looking for a problem. Which is why when the military issues cans with DI ARs (think URGI), they never, to my knowledge, have adjustable gas blocks.
Click to expand...

It's a function of the back pressure on the given silencer as much as the AR15 build. You can't make that statement regarding all silencers. Also, just because it works doesn't mean it's optimal. You might be getting a face full of invisible powder.
 
Fishbed77 said:
“Needed” and and “Useful” are two entirely different statements.

In fact, an adjustable gas block is completely unnecessary on many (if not most) AR-15 setups. 5.56x45mm produces far less gas than something like 7.62x51mm, where an adjustable block is actually useful.

I can vouch from experience that a fixed gas block works perfectly fine with a Sandman-S on my 14.5” and 16” mid length BCMs and 10.5” pistol. A 30-caliber can means there is little back pressure and a gas-busting BCM charging handle means no gas to the face.

I’d go so far as to say, except in the case of some exceptional (and questionable) builds, an adjustable gas block on a 5.56x45mm AR-15 is a more complicated solution looking for a problem. Which is why when the military issues cans with DI ARs (think URGI), they never, to my knowledge, have adjustable gas blocks.
Click to expand...


Same can, 11.5" 16" and 18". All work just fine without an AGB.
 
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