Effin-A Compensator Evaluation: Adjustable and Stackable


My Effin-A compensator arrived packaged in a prescription pill bottle with a lable that said, Take for management of recoil systems. If symptoms persist, adjust as needed. For severe cases reevaluate technique! I thought it was an interesting way to start things off, though to be frank, I worried it might be a sign the product was “gimmicky” and that I’d be shipping it back with a patronizing mental smirk. (Not the case, as it turned out.)

A little background—I received my Effin-A compensator from Jesse at Predator Intelligence via the good graces of Christian just before he left Kit Up! Predator Intelligence wanted an evaluation done. I’d read about it before, but intentionally did not read anyone else’s views on it (including his) until after I had a chance to shoot it. Christian told me to get it on the range and “try to wear it out”.

So I did.

(Actually, my brother and I did. Much as it pains me to admit it, he’s a better shooter than me. Not as good looking, but definitely a solid and experienced additional perspective to add to a review.)

Initial rapid fire string from the 25 without Effin-A Compensator, as fast as he could pull the trigger.

The Effin-A is manufactured by ARES Armor. What’s really unique about it is the way it can be customized to the shooter’s individual shooting style. I wasn’t sure what to expect, but I didn’t expect to like it as much as I did. (Nor did I expect my brother to like it as much as he did, which why it’s still on his rifle instead of back on mine. True story.)

The Effin-A installed easy, no tools required (which as anyone who knows me can attest is a Good Thing). The only thing I would say if you get one is to make sure you keep track of everything. That prescription bottle contains three locking washers and thirty-two set screws. All of mine were already in the compensator’s threaded ports, but I don’t know if that is SOP. Better to be safe and not risk losing anything.

The Effin-A is a steel cylinder ported with 7 rows of 4 threaded holes.  There’s a threaded steel cap on the muzzle. The setscrews thread into the holes for ‘fine-tuning’ the gas expulsion. The cap can be removed in order to stack a second Effin-A or other muzzle device should that be necessary.

After the initial few rounds to heat up the compensator and get a feel for it, we tightened it down and then went loud.

Right off it was clear that there was almost no muzzle flip. Just as advertised, the ports vented gases to reduce recoil to almost nothing. Most recoil went straight back into the shoulder with just a barely perceptible muzzle rise, and this, it is important to note, was with all ports open.

Per the instructions, we tuned the weapon at the 10 to determine direction of climb, made adjustments, and fired a second string at 10 using a nonstandard drill for confirmation. At the time we were testing this we didn’t have immediate access to an auto-capable weapon, so we adjusted by shooting from further back (the 25).

He shot two comparison groups of 10 rounds each as fast as he could pull the trigger through two identical breeds of rifle; one had the Effin-A, the other a standard bird cage. The Effin-A group was smaller by approximately 1/3 than the other (just under 8” compared to approximately 12”). Sight picture was more easily reacquired as well.

Initial rapd fire string to tune it, from the 25, with Effin-A compensator, as fast as he could pull the trigger.

We conducted additional tuning and experimentation, including another rapid fire (just as fast as we could pull the trigger) in 10 round strings from the 25 at a standard silhouette target. Each iteration of 10 rounds were within 5” groups. (Well, his were. It’s entirely possible that my patterns would have been slightly larger, but if they had been they’d still have been tightened considerably over my control group.)

10 round string rapid fire with Effin-A now tuned, as fast as he could pull the trigger (also from the 25).

After the rapid fire, we engaged various targets with multiple rounds in various drills and found the reduction in barrel flip to be constant and significant. Acquisition of targets, and transition between targets, was universally faster and smoother with the Effin-A than without.

In summary: The Effin-A is effective and fun to shoot. Ease of installation was surprising (nice that we didn’t need a gunsmith) and the ability to “tune” it from one shooter to another is a definite plus. This compensator gets a definite ‘thumbs up’, with two caveats: we were unable to test it on burst or auto fire (though I believe it would be equally effective if not even more noticeably effective there) and it isn’t terribly “stack friendly”. Neither of us, nor any of the other tactical officers there, felt that being stacked up beside one of these (particularly in close confines) would be too comfortable if someone had to engage. Keeping in mind the limitations we tested under (we’re shooters, not engineers, only had it on the range three times, only fired a couple hundred rounds through it, and it was tested in just about perfect weather) we absolutely liked how it performed.

Final tally: You’re definitely cleared hot to buy one, and hopefully someday I’ll get mine back.

About the Author

Kilgore & Call
Richard Kilgore and Jake Call have been writing on and off for Military.com for many years now. You can reach them at BreachBangClear.com or follow them on Instagram at @breachbangclear or Tumblr at http://the-mad-duo.tumblr.com/.
  • Steven R.

    Does it seem durable ? All those little screws could get lost very easy if they get lose.

    • ares armor

      It is nearly impossible for the screws to come loose on their own. as a matter of fact it is a good idea to use an anti-seize compound on the screws to prevent them from becoming stuck. if you do not use an anti-seize compound after about 500-1000 rounds through her it will be Very difficult to remove the screws. The concept is that once you get it fully tuned to your rifle / shooting position it becomes a semi-permanent adjustment.

  • David Reeder

    We didn’t have any problems at all. Now, keep in mind we were shooting in clear weather between fifty and sixty degrees and did not shoot thousands of rounds through it. I couldn’t say how it would perform in extremes of temperature or after hundreds and hundreds of rounds sustained fire but it certainly seemed sturdy to me. I would confidently recommend it to one of my friends (though I’d hang onto any extra screws just in case). I will be buying one for my personal rifle (the ones mentioned in the article were also personal, not agency, FYI; as always anyone with an issue rifle of some sort will want to make sure it’s within policy and procedure to modify their weapon).

  • Steven R.

    Thanks for the quick reply and thanks for the good review. I think I will pull the trigger on this in the near future.

  • T. Dubbs

    I’ve seen this question asked a few times, but have never seen a satisfactory response given by anyone in the ‘know’ on this product – maybe you can shed some light since you have one in hand…

    Is there some sort of feature in the design of this thing that ensures those little set screws won’t back out if tightened improperly or simply come loose after 2000rds worth of vibration and fly down the firing line to kill/maim an extremely unlucky, adjacent shooter? If those screws aren’t somehow captive in those holes with no possibility of coming out, I’d be really nervous having to stand next to someone using one of these compensators.

    • FormerSFMedic

      T, I can’t speak for Ares, but they did answer that question in a previous thread.

      They said that problem was thought of and addressed and after 10,000 rounds, there were no problems. I also know from my own digging, that the screws and the ports were designed in such a way that they will “bottom out” when tightened down. So 1) the screws won’t enter into the path of the bullet and 2) there is sufficient negative force on the screw so it won’t come loose.

  • David Reeder

    T. Dubbs: I can’t speak for Ares either, and to be candid it never occurred to me to ask that particular queston. However, we never saw any movement in the screws at all…but of course that doesn’t answer the “if tightened improperly” part, or the several thousand rounds question. Now that you bring it up I’m a little embarrassed I didn’t think of it myself. I’ll contact Predator and Ares and see if I can’t get someone to speak to this in here. Give them a little bit to get the message and respond, hopefully we’ll get an answer for you.

    • Ares Armor

      We have tested this exact thing. we purposefully left a screw hanging by one thread on the compensator. it took about 10 rounds for it to come out and it was not exactly a spectacular event. it merely fell to the floor. there is simply not enough pressure to cause these things to turn into some sort of dangerous mini-projectiles. However the screws should be tightened all the way down to where they “bottom out”

  • Lance

    Interesting concept of a adjustable AR compensator.

  • PredatorIntelligence

    Thanks to Mr. Reeder for the thorough Evaluation. The number one question we receive is regarding displaced set screws. Safety is at the foremost and Ares Armor saw the potential from the beginning of the design. Simple instructions are provided with each of the Comps describing how to properly place the set screws. This includes heating up the Comp by running some rounds through it and placing the screws in the desired ports. The screws bottom out for a tight fit without having the opportunity to enter the chamber.

    Ares Armor did repetitive testing focused on many aspects, but this one in particular and did not have an issue with the screws coming out. That being said, you can also add Loctite where needed if you want added assurance as another reviewer suggested He noted that by heating the comp you can remove the set screws if you want to alter your configuration to your ammunition or another rifle. Ares Armor has the confidence in the testing that they did, to say deliberate action would need to be taken to have a screw launch from a port. Safety precaution and awareness should be paramount, so we appreciate this question any time it is asked.

  • greyghost

    I purchased the Ares EFFIN a Compensator recently also. I really think this product does a great job in recoil reduction. Its like shooting a .22 caliber rifle.

    Installation is easy, just get a wrench and crank that ugly useless A2 Flashhider off your barrel.

    I only have one issue, which I must do more tests to verify its still occuring. Looking at the exit point I noticed a small gouge in the metal, It appears the bullet has collided with the lower left corner and lifted some of the metal from the compensator.

    I need to go to the range and fire some more, this could have occured within the first few rounds and now the bullet does not nik the side because now its flush.

    This may not be ARES ARMOR’s fault, It could have happend when I was removing the stubbon A2 flashhider. I have read reports of people slightly moving there barrel when trying to remove muzzle devices if not careful.

  • Diogenes

    The problem with most muzzle brakes or compensators is that they tend to increase visible muzzle flash in low-light environments. This is a crucial factor in real-world ops.

    So how did the Effin-A fare in this regard?

  • Make mine a Battlecomp!

  • Mitchell Tuckness

    Guys, will the .308 Effin-A fit a 15x1mm right twist threaded barrel? I want to buy on for my PTR-91 .308 which has that threading, but for the life of me I cannot find any info on the web that tells me it’ll fit.