With its polymer receivers, the .22 LR Smith & Wesson M&P 15-22 Sport is a particularly quiet rifle when suppressed. When integrally-suppressed from Innovative Arms? Fuggedaboutit! Adding only four ounces to the weight of the standard 15-22, Innovative Arms’ M&P 15-22 Integral is easily one of the quietest firearms on the market . . .

An aluminum shroud is permanently attached over the ~10″ barrel, extending the effective legal “barrel” length to 16.25″. So, it’s a single-stamp gun (it is not an SBR; it only requires the silencer registration). Some of the reason it’s so quiet is that there’s a lot of volume (as in space, not noise) inside of that tube, which provides the gunshot gases plenty of opportunity to expand and cool down.

Somewhere after the chamber but before the muzzle, the barrel is ported. This bleeds off gas and pressure in order to drop high-velocity ammo (read: the affordable bulk-box stuff) down to subsonic speeds.

And it seems to be just barely enough. CCI Mini-Mags averaged 1,108 fps, which is about 80 fps slower than I’d expect from a 10″ barrel and is 22 fps slower than the speed of sound at 72 degrees F air temp. Of course if it were 34 degrees out, every round I sent over the MagnetoSpeed chronograph would have been accompanied by a sonic boom.

American Eagle Suppressor .22 LR runs 970 fps out of a 16″ barrel, but I don’t know what to expect from it through a 10″ barrel (ported or otherwise). At any rate, it averaged 855 fps through Innovative Arms’ M&P 15-22 Integral. Note that single-digit standard deviation, by the way. I really love this ammo.

Though the Integral comes with a take-down tool, the end cap will accept a normal 3/8″ socket wrench.

Lefty loosey and the core begins backing out of the tube. It’s threaded into the end of the tube rather than onto the barrel. As you spin the core, its snug fit scrapes carbon and other combustion byproduct off the walls of the tube.

The 6-inch, stainless steel, monocore baffle pulls out the rest of the way by hand, ready to be dropped into an ultrasonic tank for cleaning or scrubbed down with the brushes and cleaners of your choosing.

Around to the receiver side and we find the standard S&W M&P 15-22 bolt, recoil spring, and charging handle setup. Really, if I could change one thing about this gun right off the bat it would probably be swapping out the plastic charging handle for an aluminum one. I don’t mind the polymer receivers at all and, while the polymer charging handle is sufficient, it just feels flimsy.

It’s all standard M&P 15-22 inside of the lower, too. Which isn’t a complaint. The trigger’s actually better than a normal AR-15 “mil-spec” job. The 25-round magazines are great.

https://www.youtube.com/watch?v=36nwHM1o594

And it runs. It runs and runs and runs. I borrowed this rifle from Silencer Shop (priced under a grand there) and it has apparently been through the ringer. Something like 10,000 rounds during demo days and company picnics and loans to bloggers. It certainly looked well-used, with green copper patina scale on the barrel around the chamber and that sort of baked-on, crackly carbon layer that takes dedication to build up and age like a fine wine. Or cheese crust.

Anyway, I upped the round count more than necessary and had only a single stoppage due to a primer-less round. It cycled subsonic ammo like the aforementioned American Eagle Suppressor stuff and a few brands of match-grade ammo without a hitch, and it cycled what would normally be supersonic stuff like Federal Hunter Match, Mini-Mags, and a couple bulk brands as well.

Through all of this, zero blowback detectable on my face or hands. While not often a big issue with a suppressed .22 LR rifle anyway, it was still notable in its complete absence even during magazine dumps. The ported barrel and large amount of space inside of the suppressor tube likely lead to particularly low backpressure.





At 25 yards off a sandbag with a red dot, accuracy was okay. Norma Match-22 turned in the tightest, 5-shot groups of about 0.68″. Mini-Mags netted 1.06″ and the AmEag Suppressor about 1.14″.

Not match-grade, but that’s not what it was built for. Of course, 10,000 rounds ago it may have fared slightly better. I did run a bore snake through it a few times to ensure it was at least chunk-free.

The Innovative Arms M&P 15-22 Integral is extremely quiet, which is what it was built for. From the shooter’s perspective, it seems like the action cycling is responsible for most of the noise. A bit of speculation on my part here, but if this gun were built on aluminum receivers I think it would be noticeably louder. The actual shooting part is so darn quiet, it’s all about the action.

In Silencer Shop’s testing, this thing meters at like 113 dB. That’s about as quiet as any suppressed .22 LR gets. I actually wish the M&P 15-22 had a forward assist so I could hold the bolt shut and meter it with and without the action’s action.

Numbers aside, though, when shooting this gun outside it’s quieter than a paintball gun, quieter than many BB/pellet guns, and quieter than the spring-powered staple gun we had on hand. Well, okay, quieter than the staple gun when stapling targets on wood; approximately a wash when just firing staples downrange. Perhaps the only quieter gun is a caulk gun. Or a glue gun. It’s way quieter than a tape gun.

The extra four ounces is hard to notice, but may even be a positive. A little extra weight at the muzzle helps the rifle handle a bit more like the real thing, swinging between targets and shouldering less like a toy and more like something with a bit of gravitas. With an empty mag and the stock collapsed, the center of balance is at the pivot pin. It handles nimbly and feels neutral.

This setup — sold as a complete rifle — comes highly recommended. It’s light, nimble, reliable, holds 25+1 rounds, and is a hoot to shoot. Oh, and it’s quiet. Like basement shooting gallery (where legal) quiet. Like backyard pest control (where legal) without waking the sleeping cat quiet. Like dropping the bolt on an empty chamber is louder than firing this thing and chambering the next round quiet. It’s silly quiet.

Specifications: Innovative Arms M&P 15-22 Integral

Caliber:  .22 LR
Suppressor Build:  Aluminum tube, Type 3 hard coat anodized, and 17-4 PH stainless steel baffle core
Capacity:  25 rounds
Action:  Straight blowback
Length:  33.8″
Weight:  5.05 lbs
Barrel:  10″ ported barrel with permanently-attached aluminum suppressor tube for 16.25″ effective legal length
Receivers:  Polymer
Furniture:  10″ polymer M-LOK handguard, Magpul sights, parts kit style pistol grip and stock
MSRP:  $1,150 (about $200 less via Silencer Shop)

Ratings (out of five stars):

Accuracy: * * *
Nothing to brag about, but it’ll do the trick for keeping raccoons, skunks, possums, and aluminum cans at bay. In fact, with the iron sights I was consistently hitting a 1/2 IPSC-sized steel silhouette offhand at 100 yards with Mini-Mags, and I think most misses were due to wind.

Ergonomics: * * * * 
Ultimately, it’s an AR-15. A lightweight one at that. It would be five stars with a better pistol grip, charging handle, and maybe a nicer stock. All easily upgraded, of course.

Reliability: * * * * *
Not a hitch. Appears to be reliable and durable, too.

Customize This: * * * * 
The M&P 15-22’s AR-15 parts compatibility, limited though it is, opens the door to tinkering, swapping, and upgrading many of its components.

Overall: * * * *
Holy Hannah is this rifle quiet. It’s also handy and reliable. If it shot those groups at 50+ yards instead of at 25, I’d be hard-pressed not to give it five stars. Though that plastic charging handle still has to go.

 

30 COMMENTS

  1. I have something extremely similar, an M&P15-22 integrally suppressed by Underground Tactical. I can vouch for the crazy quietness of it. The round slapping the target is louder than the report. Even indoors, the action is louder than the report. Crazy quiet. People love it. It’s the gun I shoot the most, and it’s the one NFA item I would recommend over all others.

    But I hate the trigger and its plastic hammer.

      • Yes, however some will not function correctly and some will actually break the hammer. The S&W forums have some good threads to read on the topic.

        Anecdotally I can say my CMC drop-ins were hit or miss on actually cocking the hammer. Usually two or more times per mag the hammer would not cock. The PoF drop-in that I have in there now works just peachy though.

        Finally, you need to be careful with the pins. The 15-22 FCG pocket is not quite the same width as a normal AR. If you are using pins that tighten from the outside with little screws you can damage the receiver.

    • Or perhaps a better question: Will the uppers fit on an AR-15 lower?
      Can you buy just the upper?

      • No; Smith engineered it so that the takedown and pivot pins do NOT line up.

        Also, both the upper and lower are slightly wider than an AR-15; trigger and hammer pins recess about 1/16″. KNS and other companies make anti-rotate pins that are specifically longer for the 15-22 frame. Other items such as BAD levers either need to be bent to fit the wider frame, or purchase one designed for the 15-22.

        Also, the above crap about a plastic hammer… Try again.. I have 3 15-22s, including an IA integral suppressed. All three had NORMAL, metal hammers.

        I’ve also put different fire control groups in my 15-22. I don’t believe there is any fire control group designed for an AR-15 that WILL NOT work in a 15-22 (save full-auto…). I’ve put geiselle, CMC, ALG, and a few others in mine… No issue, ever.

        Over 20k rounds through mine.. Had a firing pin break, and a single OOB. Other than that, I’ve been pleased with the purchases. And the IA integral is really really cool…. Doesn’t generate enough back pressure for a slide-fire, though…

    • The 15-22’s take ar-15 triggers so you can upgrade it to anything you want. Maybe get the new Timney Calvin Elite with the different trigger shoes and give us a review on it while enjoying you 22 even more

    • JWT and I shot the Innovative Arms M&P 15-22 Integral and his integrally-suppressed Underground Tactical M&P 15-22 side-by-side on the same day, and I sure couldn’t hear a difference in volume.

      BTW — yeah, this M&P 15-22 that I borrowed had a metal hammer. Pretty darn sure. They did go from a Gen 1 to a Gen 2 in early 2010, I do believe (like March-ish), so it’s possible this changed between generations.

  2. My stock M&P 15-22 and Ruger/TacSol 10/22 TD, with a conventional suppressor, are both incredibly quiet with subsonic ammo. Great fun to shoot.

    • John if you’re talking about a two stage version I wouldn’t recommend it geometry of a two-stage is different then the original design by Eugene Stoner which Smith & Wesson duplicated to a certain extent. It takes more Force from a bolt carrier group to Cock a two-stage trigger than it does a single stage. And being that the M&P 15-22 is direct blowback it can cause an issue with it not being able to cock the hammer.

    • You can replace with AR-15 triggers but you’ll want to make sure they use a full-power hammer spring (or something like the Hiperfire) since rimfire primers need a hard strike. Also, many won’t have that top corner of the hammer high enough to be fully cocked by this bolt. It’ll be hit-or-miss, basically. I know people have successfully run the Geissele SD3G in the M&P 15-22. Others will work, but I don’t have a list…

      Additionally, the polymer receiver is a little thicker so you’ll likely want to use threaded, locking pins since standard ones may be a little short.

      • There was another fella that just talked about the same issue as the pins being a little too short with standard AR-15 pens. He mentioned a few kits that are specially designed for the M&P 15-22 to fix this problem. Anyone know why they just didn’t internally suppressed the rifle barrel instead of cutting it short and adding a can and permanently attaching it to the existing Barrel?

  3. With a fixed stock, this thing would actually be legal in CT – Rimfire long guns are permitted one more “evil feature” than center fire. And since this thing has no threaded barrel, the evil features are just the removable mag and the pistol grip.

  4. If not for that 9 month wait….while I love me some HPA, Trump could staff up the ATF, in under a month, with enough examiners to reduce the tax stamp wait to under a month, for ALL NFA items. That would get us nearly all of what the HPA would us PLUS more.

    I’d take $200 tax and a month wait TODAY, vs no tax and no wait on some indeterminate later date.

    Let me be clear, I’m not saying that we should not abolish the NFA (and ATF) and accept a “more convenient” infringement; I just want a cookie now AND cake later. Reduce my wait now, and work to take it to zero like it should be ASAP.

    • That will be problematic – Reduce the wait time enough, the excuse will be “Why do away with the NFA at all, your lengthy wait is over.”

      Keep in mind the typical bureaucratic (lack of) mentality…

    • I would prefer if the AG, by executive order, would declare that all SOT/FFLs, in the process of conducting a NICS background check, completely satisfies NFA background check requirements. Then it’s just a matter of ‘registering’ it with the government.

      Don’t get me wrong.. I don’t like the $200 tax. However, this would require NOTHING from Congress – no HPA, and you get SBRs and SBSs too. Doesn’t help the Form 1s, but hey, ya gotta start somewhere…

  5. I’m no rocket scientist but isn’t internally suppressed or integrally suppressed supposed to be where are the barrel is left alone and the barrel itself is ported and it can is placed over the barrel so that the actual barrel length stays a constant 16 and a quarter inches in the can just comes back over the barrel? That’s just a 10 inch barrel with a can permanently it welded attach to the 10 inch barrel making it a total length of 16 and a quarter inches but you only have a 10 inch barrel you would think that is 16 & A Quarter inch barrel that is ported and has a can that runs back down over the barrel would be even quieter. Is this the only company doing this to 1522? Is this the same company that I saw not a review but actually the gun announced? Thanks for any help.

    • No reason to think that would be quieter. Would probably be less accurate, though. It certainly is another way of doing an integrally suppressed setup, but it seems like most/all companies got away from that and went to this sort of thing some years ago. Instead of bleeding off all the gas propelling the bullet while it’s still inside the barrel, they’re stripping it off and catching it in baffles afterward the bullet leaves the barrel. I think it’s likely more consistent and accurate, as well as easier to make.

      • That seems to make sense to me period if you bleed off the propellant gas while it’s still in the rifling you have a restriction on forward movement with no pressure behind it to keep propelling it at its current velocity. So basically once the gas is blood off behind the bullet and the bullet is still going down the rifling it’s going to slow down even more is what you’re saying? Sounds good to me. Makes sense.

        • Plus the holes in the barrel tend to shave the bullet and it just opens the door for reduced accuracy for many reasons. You have to machine those holes super carefully, come up with the right size, chamfer the edges to reduce cutting into the bullet and gunking up the holes, re-hone the bore to get rid of burrs and such, etc etc.

          BTW most .22 LR is at full speed by ~12″ of barrel. Most starts losing velocity in barrels 18″ and longer. This is without ports. If there was no NFA, even normal, target-grade .22 LR rifles would probably run like 12″ to 14″ barrels.

          …so if I were building a suppressed .22 I’d probably run a match-grade, unmodified barrel in the 10″ range with the can on the end. Permanently attached to avoid it being an SBR, or removable (so I could use it on other guns) if I didn’t mind the SBR thing. Either way, with a handguard that extended out beyond the barrel so it covered most of the can. (My 8.3″ 300 BLK upper is just like this)

  6. I have runa Geiselle, BCM, Wilson TTU and ALG triggers in a M&P15-22 without issues. 2 to 3k rounds per trigger.

  7. Well a couple of those triggers you mentioned the ALG and the BCM those are single stage trigger those aren’t two stage.

  8. ALG is mr. Geiselles wife’s company and they only make single stage triggers. Geissele also make a SSA trigger now as well. The SSA trigger system is single stage as well. I’m not sure if Wilson Combat TTU is single stage or not I haven’t used that trigger before.

  9. Now if the hearing protection act will just pass.
    It’s NOT an AR-15, but it has the same ergonomics.
    Everything is easily upgradable at tacticool22.com
    Aluminum charging handle and a new M-LOK aluminum free float hand guard.

  10. I just got mine but CCI Mini mag is all going supersonic for me through it. Also tried some federal 38 grain 1260 ft per second stuff and it also is going supersonic. I am in Tennessee at about 800 feet above sea level at 75 degrees and 70% humidity right now.

  11. Just received mine yesterday. Disappointed to find what looks like rust ½ way down the bore. Sending it back to see what they can do.

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