Silencer Review: AAC M4-2000 (5.56 NATO)

The AR-15 is one of the most iconic and prevalent firearms in the United States. It’s lightweight, fun to shoot, and is the firearms equivalent of a Barbie Doll (you can dress it up however you like). While the cartridge may be relatively small, the noise it makes can only be described as “obnoxious.” Thankfully Advanced Armament Corp. has a silencer to take care of that problem, and it’s called the M4-2000.

As a preface, I just wanted to emphasize that this is not a “full” review of this product. Here at TTAG we usually reserve judgment until we’ve put a couple hundred rounds through something and tried it out in different conditions. Unfortunately the BATFE here in the U.S. prevents us from getting our hands on silencers for protracted testing unless we go through months of waiting, spend $200 per transfer, and live in certain states. It’s impractical. Luckily I recently had a chance to visit the Advanced Armament Corp. factory and test all of their cans under their supervision. While the tests may not have been as complete as I want, they were good enough for a brief review.

The M4-2000 is constructed using Inconel 718, which is an extremely lightweight and strong material. The interior consists of a number of baffles which have been welded together using circumferential welds, creating a completely sealed inner core. A stainless steel skin was placed over that core mainly for show and doesn’t assist in noise reduction. This is slightly different from how other silencer companies make their cans, which spot weld the baffles and use the outer skin as an expansion chamber. Kevin explained that they too originally used that production method, but switched to the sealed core because it makes their silencers more effective and more durable.

The M4-2000 also uses the ratchet mount system for quickly attaching and detaching the silencer from the rifle. According to AAC, this provides “…precision accuracy with minimal and repeatable zero-shift.” In other words, the bullet’s flight path is only slightly affected and the shift is consistent and predictable every time. “Zero shift” is a term used to describe the movement of the point of impact relative to the point of aim that happens when a silencer is attached to a firearm, and is the combination of added weight on the barrel moving it physically as well as the silencer affecting the flight path of the bullet. Thanks to their lack of bullet wipes, AAC’s “zero shift” is almost entirely due to the added weight of the can.

I didn’t believe a silencer could make 5.56 NATO quiet enough to not need hearing protection. There are a couple of guys at the 3-gun matches I go to who use silencers on their 18″ AR-15s, and even standing 30 feet behind them the noise is too much for the ears to take and sends us running for our earmuffs. So when John Hollister handed me a 11.5″ AR with an M4-2000 silencer on it, I was expecting the same “huh, it’s quieter but still uncomfortable” reaction.

Turns out I was wrong — silencers really can make the 5.56 NATO round quiet enough to be hearing safe.

Well OK, maybe not completely hearing safe. It’s JUST this side of that 140 dB mark, mostly because of the supersonic round coming out the front. And that’s not something that’s likely to change. Unlike 9mm or .300 BLK, there is no cheap commercially available subsonic ammunition available.

The biggest complaint I had when firing this silencer was the slightly discomforting level of exhaust gasses flowing out of the back of the receiver. In semi-auto the level of exhaust was reasonable, but once I cranked it over to full auto I actually had to stop firing to catch my breath in the middle of the magazine. Not really a deal killer for the civilian population, but something for the LEOs to keep in mind I suppose.

The M4-2000 is a battle tested and soldier approved silencer for the M-4/M-16/AR-15 platform that adequately suppresses the sound of a 5.56mm NATO round going off. It’s rugged, over-engineered, and available from an FFL near you. If I’m buying a silencer I want it to work on multiple calibers and be as quiet as possible (and I did, I just bought myself a 762SDN6), but this isn’t designed to do that. It’s designed to make a ridiculously loud round slightly less loud. If you want a completely quiet gun, get something in .300 AAC BLK. But if you need your M4gery to have a little less bark then this is for you.

M4-2000 5.56x45mm NATO Silencer
Length: 6.625″
Weight: 17.1 oz
Diameter: 1.5″
Sound Reduction: 32 — 34 dB
MSRP: $1050

Ratings (out of 5): 

Sound Suppression:  * * *
I was genuinely surprised at how quiet it was. Firing an AR without needing hearing protection was an incredible experience. It’s still not completely silent, though, and the supersonic ammunition still makes a lot of racket.

Build Quality: * * * * *
It feels solid, and looked pretty damned good to me. Then again, I only had about 20 minutes to play with it.

Ease of Use: * * * *
There’s nothing to take apart, nothing to clean, and nothing to lube. It’s easy as pie to maintain. I knocked it down a point because of the exhaust issue it created on that little gun, but your mileage may vary.

Overall Rating: * * * *
This is a very specialized silencer. It does one thing and does it well: silence the muzzle report of an AR-15 rifle. It’s a one trick pony, but it does that trick very well. If I were buying a silencer I would (and did!) buy something that covers more calibers, even trading off some 5.56 NATO suppression capability for the privilege. But if all you care about is 5.56 NATO then this is for you.

(Pictures courtesy Advanced Armament Co.)


  1. avatar Ernunnos says:

    What? You dinged a product two stars because 1) a centerfire suppressor isn’t completely silent and 2) supersonic bullets have a crack? Why don’t you just ding it the other three for 3) not giving you a pony that 4) shits skittles and 5) flies?

    It would be about as reasonable. Physics is physics. Compare products to how they perform against the competition in the real world. Not against some standard formed by watching too many GI Joe cartoons.

    1. avatar Nick Leghorn says:

      I dinged it in “sound reduction” because it’s still very loud. I was still very impressed, however, and gave it 4 full stars overall.

      The “Overall” score isn’t always an average of the previous categories. In this case, the stars are somewhat relative to the other silencers I tested.

  2. avatar Ralph says:

    “there is no cheap commercially available subsonic [5.56] ammunition available.”

    Question, Nick. Commercial subsonic 5.56 or .223 ammo is available, although as you noted it’s not cheap. Aside from subsonic ammo which is admittedly “non-cycling,” does stealthy 5.56 ammo reliably cycle an AR?

    1. avatar Nick Leghorn says:

      In order to get the right pressure to cycle the action that bullet would need to be pretty massive. So massive, in fact, that I doubt it would fit in a magazine.

      I don’t have any proof to back it up, but I’m going to say “no.”

      1. avatar Dean says:

        subsonic ammo is made to be shot out of a gun with a sruppresoor on it it is made for that.with out a suppresoor the gun will NOT cycle the subsonic ammo the suppresoor traps some of the gases and helps with the cycleing of the round.and subsonic ammo for the 556 and 233 is available on line for cheap you just have too look.if you shoot surpersomic ammo out of a gun with a suppresoor on it yea it is going to still be loud it is SUPERSONIC AMMO!!! DUH!!! I( spent 13 years with the Marines i know how suppresoors work and how to use then I own 4 of them all AAC silencers.

        1. avatar Greg says:

          Semper Fi Brother! I was wondering if you could provide me with the website(s) selling the 5.56 subsonic? Thanks.

        2. avatar Antagonist says:

          Didn’t know the marines had anything to do with suppressors.

  3. avatar Giao Nguyen says:

    I will be eagerly waiting your review of the 762SDN6.

  4. avatar Chris Dumm says:

    I would love (as if I’ll ever have the cash) to get a can for my AK-74, but I’ve read that AKs are very tricky to suppress. Even if they weren’t, the corrosive ammo would quickly ruin a sealed can suppressor.

    1. avatar Nick Leghorn says:

      These guys actually made an AK in .300 BLK. It uses a 762SDN6 can and works pretty well.

      And by “works pretty well” I mean “jams every 5th round and is still too loud.”

      It’s something to do with the gas system.

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