Monday, July 14, 2014

CMMG Beyer Dedicated AR15 .22LR Upper Build Review

CMMG Beyer Dedicated AR15 .22LR Upper Build Review

We all want to shoot more .22LR now that our beloved .22LR ammo seems to becoming available again at reasonable prices. For the AR15 shooter, there are a couple options. The first option is to just buy a dedicated .22LR AR format rifle such as the S&W M&P15-22 or one of Umarex’s Colt .22LR models for a little under $500. Another option is to build a dedicated upper or use a drop-in .223 to .22LR adapter Atchison/Ciener style conversion.

The drop-in conversions are simple and allow you to use your existing AR15 5.56 barreled action with just a bolt and magazine swap. The technically allow you to shoot .22LR ammo out of your .223 chambered rifle, but the sacrifice is that they generally deliver poor accuracy and reliability. 

The main reason for reliability issues of these conversions is that they usually require a higher power hammer spring to assure reliability which then requires very high velocity rounds to provide reliable cycling and charging of that heavy hammer spring. Accuracy suffers due to two reasons; because of the jump the bullet has to make down the conversion adapter throat to the rifling and the faster twist of a typical AR15 barrel which destabilizes the slower and shorter .22LR round. The result of using .22LR AR15 conversion kits is usually frustrating reliability and marginal accuracy.

If you want to shoot .22LR from a standard AR15 lower, then the only real option is to go for a dedicated upper receiver. Although high hammerfall force is still required for reliable ignition, I lusted for the accuracy potential a dedicated .22LR AR15 upper could deliver.

One of the leaders of very high quality .22LR conversions has been CMMG. CMMG has continually pushed the design envelop of the original .22LR Atchison/Ciener AR15 Conversions by creating an updated design which is more reliable, user friendly, with more available optional add-on features such as forward assist and last shot bolt hold open. The CMMG conversions are also fully compatible with the large supply of BlackDog .22LR AR15 magazines I already had on hand from drop-in AR15 .22LR conversions. BlackDog X-Form magazines are pretty much “THE” standard magazine of choice for almost every dedicated .22LR kit out there.

I previously tested the ATI Chiappa .22LR upper which delivered OK accuracy, so this time I decided to do my own build from the ground up using a .22LR Match grade barrel. My previous experience with Beyer barrels has been positive, so my thought was to use one of their cool looking fluted match AR15 .22LR barrels for this build.

The general build specs of a dedicated AR15 .22LR upper is very similar to any other AR15 upper build. Actually, all the components are the same except for the dedicated barrel, barrel collar, and bolt assembly plus you can omit a few parts. The .22LR action is recoil operated with bolt movement limited within the length of the .22LR bolt carrier which does not have forward assist capabilities so you can omit a gas block, gas tube, and forward assist on the upper and the buffer spring and buffer on the lower receiver. If you already have a favorite lower receiver build, the buffer and buffer spring can be left in place when swapping between your 5.56 upper and .22 upper receivers, but just note the .22LR carrier does not reciprocate into the buffer tube.

You can use the same charging handle, upper receiver, barrel nut, and free float handguard as you would with any AR15 build. If you want a .22LR replica of your favorite AR15 upper, you can build it in .22LR. For this build, I used a Beyer AR15 Match Barrel with CMMG complete .22LR bolt carrier and barrel collar. The barrel and carrier slipped into an Aero Precision upper with a Parallax Tactical Slim 15” forend.  I initially left off the forward assist simply because the one I had was needed in another 5.56 build, however later on after the photoshoot, I installed one to complete the look of the build. Had I thought a little further ahead, I should have use one of Aero Precisions No-Forward Assist uppers.  

The initial upper build was complete in about 5 minutes after slipping in the Beyer barrel in the Aero Precision Receiver, installing the Parallax Tactical Slim barrel nut and forend, and finally sliding in a charging handle and CMMG bolt carrier. The barrel collar on the CMMG carrier just snaps on and off the Beyer barrel and can be removed or installed easily without tools for cleaning. I added a giant .22LR Tactical Innovations Muzzle brake. Done!  

I topped off the build with one of my favorite .22LR optics; the Nikon P-Rimfire 2-7x32 Matte BDC 150. This variable scope offers a really low 2X magnification for fast moving targets and up to 7x magnification for more precise target shooting. This P-Rimfire model features a swappable turret design for dial and shoot capabilities at extended ranges. Nikon supplies two turrets; one aligned to high velocity round and another for standard velocity rounds.  This allows for a pretty easy way to hit larger range targets with just the twist of the knob. Nikon also has other models with built in BDC (Bullet Drop Compensating) reticle.

I did go all out on the lower, simply because I needed “yet another” killer lower receiver to use for other builds.  I snagged one of Aero Precision’s newer Ambi Lower Reviewers with BAD ASS Ambi Short throw Selector. 

This receiver looks like any other standard Mil-Spec profile Lower receiver, however it features an ambi-bolt release lever on the right hand side and has markings specifically set up for the Battle Arms Development Short throw Selector switch. Having tested many manufacturers attempts at delivering ambi bolt release controls, I have to say that I think Aero’s design is one of the more common sense and user friendly of those I have tested.

Because I was already spending the money, I decided to upgrade to a Hiper-Tough Hiper-Fire 24E match Trigger to deliver that high hammerfall energy the .22LR detonation requires and really freaking awesome trigger feel. The rest of the lower receiver was completed with Mission First Tactical’s ENGAGE Grip and BATTLELINK Minimalist stock, a Barnes Precision Machine lower parts kit, and KNS Precision - Anti-Rotate Pins to dress things up a bit. The final completed lower receiver delivers a great blend of looks and performance.

The quality, fit and finish of the CMMG bolt is excellent. I previously tested an ATI Chiappa upper and there is zero comparison between the low end ATI quality and what CMMG is delivering. The CMMG design is a huge upgrade.  Just like my previous Beyer barrel for my 10/22 build, this AR15 version features the same high quality fit and finish which is a step up from Tactical Solutions aluminum sleeved barrels. The Beyer barrel is more precise and more durable due to the 7075 aluminum sleeve versus competitors 6061 sleeves. Beyer also uses a proprietary Benz style .22LR match chamber which I have found delivers a good blend of accuracy and reliability across a wide variety of ammunition. There are all metal full weight barrels on the market, however for a .22LR I believe it is better to keep weight down to encourage use by younger shooters.  The Beyer barrels are definitely light, but just a bit heavier than typical aluminum sleeved barrels.

The Tactical Innovations giant muzzle break does nothing other than look cool. I had it rattling around in my parts bin, so I thought this build would be a fun use for it. The TI brake slips on to any .920 bull .22LR barrel and is secured via a set screws. In this case, I just secured it to the removable thread protector on the end of the Beyer barrel. Its a fun accessory, not a performance upgrade.

Functionally the build works well, however initially I did have some cycling reliability issues with standard velocity (sub-sonic) ammo such as CCI SV, SK, and Lapua, however high velocity rounds delivered the near flawless functioning I see from my M&P 15-22 rifle right out of the shoot.  The problem is that as any match chambered barrel, the Beyer barrel really performs its best with standard velocity rounds.

Over the last couple months, I have noticed that a couple thousand rounds later, my reliability went way up, so I have less and less problems with the Beyer barrel’s prefered high accuracy ammo. My best group with Lapua Center-X was just under ½” at 50-yards which is excellent for an AR15 .22LR upper. By contrast, the three drop-in .22LR AR15 conversions I have tested barely could hold 2” groups at 25-yards… one delivered far worse accuracy. The M&P 15-22 is not inaccurate, but it cannot come close to delivering ½” 50-yard groups.

A dedicated AR15 .22LR upper is the way to go for those who want accuracy. Winchester M-22 ammo functioned perfectly as did a bulk Survival Tin of Federal .22LR HV ammo. My best groups with high velocity ammo were from CCI Velocitor ammo which coincides closely with my accuracy results of the 10/22 Beyer barrel I tested previously.  I did find that I needed to keep the CMMG bolt well lubed or I started seeing various reliability issues at the beginning. About every couple hundred rounds, reliability was returned with a solid oil soaking of the carrier.

Of note the HiperFire trigger is really a magically upgrade and seemed to all but eliminate light strikes. A great trigger which I like more and more.

There are some teething pains and a pretty long break in process for one of these builds, however I don’t think anyone will complain to much. In some ways I had these same issues with customer 10/22 builds. My customer Kidd 10/22 rifle is just now finally humming along after about 2000+ rounds.

Is the cost of a dedicated .22LR upper justified? Well, its easy to justify from a cost saving perspective now that .22LR ammo is returning to the shelves at reasonable prices. Even a high end dedicated .22LR AR15 upper, such as this, can pay for itself quickly just as a trainer. Add in that you are spending more time behind the same lower receiver you shoot defensively/competitively/hunting, and its a big win for building gun familiarity. It is also a great option for those who want an accurate .22LR upper for their favorite AR15 lower receiver and you can even build the upper with the same components to replicate the feel of your current .223/5.56 upper. Obviously, for the cost I have invested in this upper, I could have just purchased a complete S&W M&P 15-22 or Umarex .22LR AR15 model as these are regularly on sale for under $500. Doing that would not be quite the same.

For me, I have an M&P15-22 and have had the Umarex models, however I wanted a dedicated upper which worked with my existing lowers and delivered better accuracy and reliability over my previous ATI Chiappa upper. This build works well enough for me as long as I keep it well lubed and fed with high velocity rounds and most importantly, it has been an absolute blast to shoot.

Beyer Barrels
Fully machined to precise, match grade tolerances from exceptionally hard 7075 aluminum
Light weight ranging from 13-18 ounces
Barrel shanks are oversized to .001" and may require a little sanding to fit receiver
Barrel: 22 LR Ultralight Target, AR15
Price: $244.00
Caliber: 22 Long Rifle
Chamber: Custom Beyer Match .22LR Chamber with recessed target crown
Finish: Matte Black
Length: 16.5
Diameter: .920
Twist: 1-16
Options: Fluted
Product Notes: Threaded

CMMG Dedicated .22LR Bolt with Collar - 22ARC - MSRP $219.99
Tactical Innovations - M110™ MUZZLE BRAKE .22LR BULL BARRELS - $29.99
Aero Precision Stripped AR15 Upper - $79.99
Parallax Tactical Gen2 15" Free Float Super Slim Rail (FFSSR) - $199.99
Nikon P-Rimfire 2-7x32 Matte BDC 150 - Reg. $179.95
Black Dog X-Form Magazines - 10-30 round magazines available - $20-$30

Aero Precision Ambi Lower Reviewer with BAD ASS Ambi Short throw Selector -  $250
Hiper-Touch Hiper-Fire 24E Match Trigger - $225
Mission First Tactical - ENGAGE Grip and BATTLELINK Minimalist Stock - $89 Street
Barnes Precision Machine - Lower and Upper parts kit - $69.99
KNS Precision - Anti-Rotate Pins - $29.99

Shop a huge selection of Firearms and CMMG Accessories at - excellent prices and huge selection.

Also used in this build
Parallax Tactical -
Tactical Innovations -
Mission First Tactical -
Battle Arms Development -
Black Dog X-Form magazines -
HiperTouch HiperFire -
Barnes Precision Machine -


DontCome2MyHouse said...

Great writeup. I will be using the TACCOM bolt carrier. I'm using a milspec trigger in my AR lower. Are you saying that should use a heavier trigger spring to prevent light primer strikes?

Major Pandemic said...

Yes - Heavier trigger spring will really help out with reliability.

Unknown said...

Hi, I am using the same hiper-touch 24 elite trigger in my ar15. The trigger is amazing and function flawless with 5.56. However, when I use it with the CMMG 22lr kit in the same gun. there's no bang at all. I realize the position of the fire pin in the conversion kit is a little higher then the 5.56 bolt carrier. How did you solve the problem? Can you please tell me which spring did you use in the hypertouch and what ammo? Thank you very much

Major Pandemic said...

A couple things I would try. Sometimes the CMC carrier need a little polishing on the arch just under the firing pin. This smooths things out. If there is no detonation, you may want to swap the stock Hiperfire hammer spring for a stock AR15 hammer spring. I have found that this can increase hammer force and improve detonation.