View Full Version : Short 5.56 cans

03-04-2017, 08:17

Am interested in adding a can to my 16" AR. rifle is my training rifle, SHTF rifle, and possibly sharing HD role with 12g and sidearm. I don't want to add huge length, might consider going double stamp down the road but don't want to do both at once. I don't even really expect hearing "safe" out of this, mostly just want to cut down on noise to avoid having to double plug and also so if I did have to use the weapon in a non-training scenario, preserve some degree of SA and minimize damage.

Was looking at the Innovative Arms Grunt Mini, which would put me right around 20" total barrel/suppressor and right at about 140db. Anyone have other suggestions?

Looking to stay 5.56 as I want a setup with wide ammo availability/low cost and to quiet what I use most often. Might do a blackout build down the road, but for now just looking at 5.56.

03-04-2017, 12:27
Surefire has a SOCOM556- Mini that is only 5 inches overall length. Another option for ya to look at.

03-05-2017, 11:30
I've got the AAC Mini4 and SAS Eadrom MX. Both only add about 4" to length past the brake. Since AAC was sold to Freedom Group, I haven't bought any of their stuff but it's a neat little can. While not "hearing safe", it's plenty comfortable to shoot under cover (range roof, indoors, etc.) with no hearing pro. The SAS seems quieter that the AAC. It has a "thread over mount" so it is more like a direct thread than the AAC, Surefire, etc.. but you still have the brake if you're not shooting with a can. Also a little more repeatable.

The Surefire is a great can but I think you're paying some for the name. I've got their 556RC and 556RC-2 (they're 6.2") and on a 16" rifle, they don't feel long.

Another company is Griffin Armament - M4SD-K only adds 3.5" overall past the mount. They routinely meter very well.

The only reason I'd not do the Innovative Arms is the direct thread unless you're always going to have the can mounted. I know you'll never pull the can off during combat (it will burn the be-jesus out of you) but it is nice for transport to not worry about dinging threads or needing a thread protector. (I very much like direct thread cans for precision rifles but not AR's).

Another thing to consider is cost of mounts. If your AR is dedicated to that can, not a big deal, but let's say you have 3 AR's and you only want one can. The $130-150 per mount adds up. That's where the Griffin has an advantage is you can use A2 flash hiders on their M4SD cans.

Just so you can see some lengths (I know you're not interested in a .30 cal can but threw some in the pic just for reference).

SAS Reaper MX (.30)
SAS Eadrom MX
Griffin MDSDII (not the short version)
AAC Mini-4
SF762Mini (.30)
SF762SOCOM (.30) - It was used on some versions of the Mk13 rifle
Rugged Surge in short config (.30)

Hope this helps...

03-06-2017, 06:55
I just received my Silencerco Omega 9K and Osprey 45.

The Omega 9K is for my Sig P938 & P229,,

BUT It is rated as GTG for 300BLK FULL AUTO & FULL POWER

9mm: 131.5 dB
.300 BLK SUB: 133.7 dB
.300 BLK SUPER: 138.4 dB

DISCLAIMER: I need to talk to the factory,, but full auto and full power 300BLK,, May make this an occasional 5.56 SBR can??

Took both to the range,,

The Osprey 45 w/P220,, 2 boxes with zero FTF, FTE, no problamo..

The Omega 9K,, not so good,, Worked find with a 1/2 box a Speer short-barrel, but a box of Tulammo 9mm,, 20% FAIL. I attribute the failure to a combination of weak ammo and poor recoil spring match..

PS: For the curious,,
Purchased May 20, 2016
Cashed May 31,
Released, Feb 23-27, 2017,

Picks: P229 & P938

03-07-2017, 20:37
JJ, I would think 5.56 pressure would be brutal on the 9k. SBR pressure far worse. The stellite might handle it, but would question the hoop stress on the tube. Please post what they say.

For short 5.56,

Centerfire suppressors tend to have more volume and less baffles to accomplish the task. Going shorter decreases efficency in overall Db, while increasing work/stress per baffle and chamber. Many of the the high performing centerfire suppressors have less baffles per volume but different geometry to diffuse and redirect the high pressure. This pressure delay created with increase or decrease in dwell as a function of volume and cartridge, will also effect your back pressure.

You need to be below 140 to be hearing safe. I think even 138 is still pretty loud. But, just because it is brief impulse noise does not mean that it is not damaging in long term duration endurance. Perception of tone matters too in our physiological response IMO.

Short suppressors will remove some bark of the muzzle, but generate more heat, more sound, and more backpressure depending on the design, comparativly to a full size. I would recommend some kind of adjustable gas block, like micro moa or the alike to tune a setup like that. A longer barrel would be better than a Sbr with a short can if you want comfort and weapon reliability in the long term. Otherwise you are retuning the port size and gas dwell to get what you want. Your ammo of choice will decide your setup for proper tuning.

Quick detach centerfire rifle suppressors are generally louder because you are taking away more vessel volume with the detach assembly. They also add more weight. So in many ways for db reduction, a thread mount is better. Reflex is another option, but more first round pop.

03-10-2017, 23:03
Good to see that you aren't looking for hearing safe with a short can for indoors with std 5.56 ammo.
I'm a 02/07 manf (that just means I can make and play with this stuff legally) and we have been testing some ideas. Some of what we have learned or found out from others is that the super sonic crack from std velocity ammo is still quite loud and hurts when under covered shooting platforms or even under a tree canopy. Subsonic ammo can fix that, but typically won't reliably cycle an AR15 without making changes to the gas system (that's a long discussion that's prob beyond the scope of this).
The sound signature from a 5.56 can vs a .30 can is pretty much the same maybe with a slight difference in tone, but volume appears to be very similar. I tested this with two can from the same manf, both screw on. One 5.56 and the other .30(up to 300WM).
So what I'm getting at with the above information is that if you think you might also do a .30 rifle at some point and might want to suppress it, get a .30 cal can that is rated for the most powerful ammo you will shoot. Unless you want to buy more than one. That gets expensive so why not get one tool that does the same job for multiple rifles equally well?

As far as SBR. If you are interested in keeping it to one stamp and don't need to have the suppressor removable, you can have the suppressor welded to a short barrel. Just make sure that the overall barrel length is over 16" when finished.

Hope this helps.