Concussion reducing muzzle devices and linear compensators

[Dr.Zubrato]

Is there any formal testing or evaluation by any site or youtuber to include the reduction of muzzle blast, or redirection forward of the muzzle?

I have looked at more than a few devices, including the following:

Levang Linear Comp
KAK flash can
Kinetitech muzzle brake/sleeve combo
Amazon Krink style knockoffs
KAW valley precision
Simple Threaded Device
Damage Industries Muzzle Projector Mk I

I'm currently using the Levang Linear comp on a 16" mid length. It works well, but it definitely has rust issues. Stupidly rather than return it, I chose to try bluing over the parkerizing which worked alright. It rusts much less now, but I definitely have to keep an eye on it.
A second consequence, is that due to the extra chamber it generates more back pressure and increases the fouling behind the firing pin area to include the fire control group of the receiver.

Any advice, or experience with the above muzzle devices, or better within a budget range of $60?
I'm interested particularly in the Kinetitech, KAK flash can, Damage Industries, and Levang comp to compare effectiveness?

 

[Jackal]

Linear comps generally dont do anything that a bare muzzle crown doesnt. They just add weight. Get a Seekins thread cover for around $10 and your good to go without the weight. Otherwise, invest in some good ear pro, because regardless of what you mount on the muzzle, your ears can sustain permanent damage.

 

[Gordon]

Noveske Flamin pigs work great, some of the 4 piece Krinks work well if safe , The Troy Claymore works about half of a flamin pig .

 

[Tirod]

As to testing there is very little with linears, and those included in muzzle devices are rated on flash, recoil, etc for muzzle brakes.

What linears do very well is direct all the gas to the front, not out the sides, and under testing they do, as a class, reduce the decibel rating as measured near the shooters ears. That is exactly their purpose and they do it well compared to a A2 or most brakes.

Muzzle devices aren't interchangeable - those ports are put in places for specific reasons, and they angle the gas to the sides and up to cut recoil and muzzle jump. Just don't forget they first appeared on much larger calibers and migrated down to the AR as competition oriented money makers.

I choose BRT simply because published results showed a reduction of noise at the ear, at when I was building a 6.8 they were more available off the shelf. I choose BRT again because of what I had read in tests and because it's small and nearly the same weight as an A2 - unlike all the massive heavy shields that fill the handguards on a lot of boutique builds. The BRT was about as close to A2 in looks as I've seen on the market and is suppressor compatible.

As for handling flash it's variable - depends on what ammo you are shooting to a high degree. Milspec ammo uses the cheaper Ball powder and plenty of it, commercial tends to use modern powders with a lot more flash suppressant. Mk262 does, too. I goes to the spec and supplier who makes it.

If flash is an issue shooting at night, ammo is a cheaper variable to control it rather than spending a lot of money on a muzzle device we can't research. But - the market is full of stuff that sells because it can, not because we need it. It's an 18-35 male jock market and cool for the sake of social standing does a lot of justification.

 

[Z-Michigan]

Andrew at Vuurwapen Blog did a very detailed and methodical test on a number of devices including the STD, various flash hiders and brakes. The STD did OK. His report is at the link that follows, but for me some of the key charts are no longer appearing:

http://www.vuurwapenblog.com/uncategorized/ar-15-muzzle-device-comparison/

One interesting and surprising result was that the AAC Blackout flash hider was the quietest, for the shooter, of all devices tested including the STD and a bare muzzle.

I've done my own informal testing at the range, back to back in the same session with the same rifle and ammo, and have found that the AAC Blackout is indeed very quiet and has next to no blast to the shooter. I tested it along side the STD and the Kies "blast master" which is very similar to the Levang and other linear compensators, and the Blackout was at least as pleasant to use, with no significant difference in felt recoil. I would highly recommend it if you want something quiet.

As a bonus, you can currently get a new AAC Blackout, minus packaging, for just $30 from CDNN:

http://www.cdnnsports.com/ar15-223-flash-hider-non-silencer-aac-20895.html

If you decide that you want a linear compensator instead, I would take a look at ARP's JAL, which is probably as functional as any other but smaller and lighter than anything but the STD:

http://www.ar15performance.com/inc/sdetail/2121/29944

Both of those devices are available for other common calibers if you aren't shooting .223.

 

[barnbwt]

Makes sense that a forked flash hider would do fairly well; no surfaces to reflect sound back at the shooter, and a much more gradual increase in volume for the blast bubble to expand along than a bare muzzle (directing it forward a tad as opposed to the typical spherical expansion of bare muzzles). Does the AAC ring like a tuning fork like pretty much every other forked flash hider, though (that's always been the downside of this otherwise 'ideal' shape)?

Having seen what muzzle blast actually looks like, I'm understandably a bit skeptical linear comps do anything more than a longer barrel would. Reducing flash or recoil; those can be very easily understood by virtue of the device shapes. Somehow making that spherical bubble go 'forward' despite the inherent nature of a shockwave to expand in all directions seems very dubious. At best that bubble starts out a few inches further away (which actually makes all the difference in the world for a short barreled gun with relatively low volume of burning gas like AR carbines), but that's no different than a longer barrel, except muzzle velocity isn't similarly aided.



TCB

 

[Z-Michigan]

As far as I can tell with earpro on, the AAC Blackout does not ring when shooting it. If you hit a single tine on a hard surface by hand, it will ring a bit. It doesn't ring nearly as much as some other tine flash hiders I've used, such as the Austrian FAL (Stg-58) hider.

I think the linear-compensator devices may provide some benefit by providing an expansion chamber into which the propellant gases can expand and meet the outside atmosphere at slightly lower pressure. I would guess that the effect is similar to a longer barrel with the same increase in volume as the device provides. In testing the Kies version at a private range I found that it really did seem to throw noise downrange as evidenced by a noticeable echo from a treeline 400 yards away, which I did not hear using any other device. However, I don't think they are a particularly effective option relative to some basic flash hiders when considering cost, weight, and length.

 

[barnbwt]

...or especially compared to the silencers they are clearly mimicking as much as the ATF allows

TCB

 

[Jim Watson]

Ah, but what does the ATF allow?
I once read that ANY reduction in muzzle blast was enough to get a device defined as a regulated silencer.
Have they slacked off?

 

[Tirod]

The ATF hasn't slacked off, they banned the SIG comp which was basically the inside casting for their suppressor. Apparently too many baffles seems the line in the sand. They tend to allow 1 - one - and more than that it's decided to be a "moderator" and classed as a suppressor. On a purely tax based assessment for harvesting money they have the courts working with them hand in hand. The SIG lawsuit lost it's current decision so we're waiting for whether there's an appeal.

The XM177 had a moderator back in the '60's and that seems to be where a lot of this started. Ok for military, fee for civilians.

ARP noted on the web page up 2-3 years back what MD had what Db rating at the ear, and the BRT was lower than most. On the geometric scale that rates noise a loss of 1 Db is exponential - noise is rated geometrically, not with some linear addition. Just a few Db makes a significant reduction.

Again - if there are slot or ports, the gas comes out the side of the MD, which effectively turns it 90 degrees toward the shooter. The result is that the blast of a linear is propelled forward, about 270 degress from the ear, where the brakes reduce it to 180. That's going to increase the level of sound impacting the ear. Most testing shows it.

The issue is our ears aren't a valid device for measuring it. Previous exposure, sensitivity, anecdotal experience, and what ear pro we're wearing if it's worn properly make a difference. It's about as effective as the "seat of the pants" dyno hot rodders try to use. Basically useless. We aren't capable nor trained to make a valid assessment based on an empirical standard.

It's quite nice to experience the BRT not ringing my ears when hunting in the woods, but having gone one step futher to the use of electronic muffs I'm at the point where it's basically window dressing. The only time it might help would be indoors shooting - nothing is going to mitigate the sound blast better than muffs, regardless.

The point of the brakes, comps etc is to cut down muzzle rise and recoil on the AR15 in this case, which is minimal considering where brakes started. 30 years ago nobody used them - except on a few specialty guns like the .50 BMG single shots. They were something crew served weapons had, and as the tech trickled down there were basically more justifications dreamed up for less return on the dollar.

Like to see a more level playing field in 3Gun? Mandate A2 flash hiders only. I don't think you will see as much a change in scoring as we think. And that's where brakes/comps have most of the application. SBR's to some degree, but they are more a fashion item these days than anything else. We don't get into running gun battles where a split second difference in timed doubles makes a life and death difference. It's on the sporting range where you might find yourself a place or two higher.

I've bought mine, but I understand what little they do for the money. I'm better off with muffs. My guns aren't going to see massive improvements unless I shoot massive quantities of ammo and improve my skill level enough to literally see the difference. Most can't - the skill level isn't there. That's why muzzle devices are largely a dress up "race" part for those with disposable income, a status accessory.

I note that we rate them for decibels and reduction of recoil etc but nobody tests for the amount of improvement in second shot timing or accuracy. And considering the gun is 2MOA capable by .Gov standards on 18MOA targets, any criteria smaller than that is a niche application. Either a sniper working a hostage standoff under 150m or top tier competition. Anybody blasting dirt berms for fun, it's dress up.

 

[agtman]

Noveske Flamin pigs work great, some of the 4 piece Krinks work well if safe , The Troy Claymore works about half of a flaming pig.

Agree about the KX3, at least if we're talking about ARs.

Over the years, I've shot two different KX3s and both were equally excellent at re-directing all that lateral, concussive muzzle blast, noise, and flashy-flame downrange at the target. More than once, too, someone on the firing line pointed at my KX3 and asked, "what make of can is that?" The primary downside of the KX3 - apart from not effecting enough real decibel suppression to be hearing-safe - was the weight it added it to the muzzle.

All that said, in the last two years I've gone the suppressor route for genuine hearing-safe fun. My 5.56mm ARs presently use two different quick-detach suppressors of reasonable weight. Having shot several tactical courses now in "suppressed mode" (using a 16" carbine and a 10" SBR), I don't miss the KX3s.

 

[barnbwt]

"Ah, but what does the ATF allow?"
Only The Shadow knows, I suppose. This SIG ruling judge mentioned three or four inches being the limit for length, but didn't put his foot down. I'd say a large diameter or lengthy comp chosen/designed for blast mitigation reasons (I'm looking at those stupid blast deflectors) is likely on shaky ground if the Bureau's evil eye takes notice.

TCB

 

[Dr.Zubrato]

Thank you guys for the wealth of knowledge and experience.
After comparing some of the different muzzle devices for similarities, the common feature seems to be a separate area for the gasses to expand, and then continue into the atmosphere.
So I chose the KAK flash can, and I'll give an update within a few days how it works on a 16" barrel.

My state does not allow for suppressors, otherwise this would have been a moot point.

My purpose is not a quick follow up shot, as this is for a home defense carbine in the event I wouldn't have the chance to grab my ear pro, to deafen myself or my family.

Follow up shots, weight, etc are all secondary to the direction of blast.

Just trying to do the best I can with the resources I have.

I do agree that muzzle brakes don't make such a huge difference in real life, but are more likely detrimental to working indoors, or with a team.
The more effective brakes ive seen are the most brutal to stand next to, even with awesome recoil reduction it isn't nearly worth it to have to wear plugs and muffs with a 16" barrel and still feel that pop in your nostrils..

 

[agtman]

* * *
So I chose the KAK flash can, and I'll give an update within a few days how it works on a 16" barrel.
My state does not allow for suppressors, otherwise this would have been a moot point.
My purpose is not a quick follow up shot, as this is for a home defense carbine in the event I wouldn't have the chance to grab my ear pro, to deafen myself or my family. Follow up shots, weight, etc are all secondary to the direction of blast.
Just trying to do the best I can with the resources I have.

I do agree that muzzle brakes don't make such a huge difference in real life, but are more likely detrimental to working indoors, or with a team.
The more effective brakes ive seen are the most brutal to stand next to, even with awesome recoil reduction it isn't nearly worth it to have to wear plugs and muffs with a 16" barrel and still feel that pop in your nostrils.

Brakes are brutal enough outdoors, and I wouldn't want to be you next-door neighbor if you touched off your 16" AR with a brake inside your house ... I'm still thinking your best choice, among limited options, is a KX3.

Given that your state sez suppressors are a "no-no," the real question in your situation is whether during something like a late-night home invasion you'd have the time and presence of mind to gear-up with ear-pro & eye-pro while keeping track of your family and the thugs running thru your house and/or up the stairs to attack ... ?

In other words, in a real world incident, there'll be a lot going on - with confusion, distraction, disorientation, etc. Not saying there's no solution, just something to think about.

 

[Tirod]

Plenty of folks point out that you won't have time to gear up because thugs will be bursting into your bedroom or you wake up with a knife against your throat. If that was accepted as truth there would be no nightstand guns because they would only arm the thugs further. You would be helpless, impotent against their power to get past your defenses with ninja stealth, so quiet they could walk past your sleeping Dobermans, so stealthy your infra red alarms never trigger, so crafty that they even know which step in the stair case has that squeak that told you the kids were raiding the frig at 2AM.

Yah, in the face that, we should just not even try. It would save us a lot of money being resigned to the fact that someone wanting to get into our home will always be 100% successful and we have absolutely no defense against it.

The reality is that most intrusions start with a knock on the door - and if you are not wearing the gun on you at that moment, and then open the door -? Which is what happens most of the time. Much less the two factors that are top on the list of reasons to come in - you took your drug lords inventory and are selling it off, or you took a wife beaters current GF and he wants her back.

So far that's three stupid decisions that all are included in the reasons most home invasions happen. On the other hand, the list of homeowner's found in bed with the throats cut in their sleep? Well, in a lot of those cases, it was a known family member or friend living there. You let them in.

If someone starts breaking glass and busting down the door, you still have to go to the room you keep the gun. Taking another two seconds to put on ear pro is a lot less the problem than Not Having The Gun On You. The idea that ear pro is silly is what IS silly - no thought behind the reality of what IS happening in the real world in these cases.

"You won't have the time to put it on!" = you won't likely make it to your gun before they drag you down and beat you.

While in Texas you might wear a "barbecue" gun to a back yard party, but what is being advised for those who live in that bad a neighborhood is to wear it grilling on your own deck anyway. Goes to a handgun works better for that than an SBR/AR pistol.

Lets use some common sense about it. If you can't go suppressed, and you think you will likely be shooting without ear pro, use a linear but expect hearing damage regardless. At least with a linear you throw all the blast right into the face of your opponent, not redirect it into the face of your wife or kid standing next to you at the wrong moment. Brakes have no place other than a competition rifle range or crew served weapon who are trained to keep back.

Note that teams wear eye pro, and their muffs are also their comm headsets. If you hear the wrong squeak in the night - and reach for your nightstand gun, why not amplified electronic muffs, too? You then have a better hearing advantage over your night ninja intruder, and won't miss the sound of your Dobermans taking him down - or stepping on the Lego the kids left out in the hall, again.

Frankly, they were the first line of defense back in the day.