CMMG .22 LR AR-15 Conversion Kit

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  • Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,257
    HoCo
    Anyone try the CMMG .22 LR AR-15 Conversion Kit for their AR?

    I hear people saying accuracy is horrible, key holing at 25 yards, big groups.
    But I also see some review videos with decent accuracy @ 50 yards
    When I look at reviews, the reviews are mostly good but with some bad.
    I can imagine, depending on twist rate of the barrel and the bullet weight, it can be different.
    I have both a 1:9 and 1:7
    I also have a slew of different brands of 22LR to try it in.
    My main purpose is offhand at indoor ranges. @ 25 yards

    Anyone want to chime in on what they have experienced?
    If possible, include ammo used and twist rate of barrel.
     

    clandestine

    AR-15 Savant
    Oct 13, 2008
    37,029
    Elkton, MD
    I have seen accuracy issues, but its not just Spikes, its Ceiners too. The conversion kits seem to like 1/12 barrels best, but 1/9 works for some people. Leading up the Gas Block/Front Sight Base, and Gas Tube with lead fouling is another issue.

    In my experience there are better options, such as a 15-22 rifle. If you don't want a dedicated rifle, get a dedicated conversion upper, but be prepared to spend more for that than a 15-22.
     

    photoracer

    Competition Shooter
    Oct 22, 2010
    3,318
    West Virginia
    I used a CMMG conversion kit for awhile. In fact the cheap AR I built to use it ended up being used on the 2nd day of the 2012 Ruger Rimfire World Championship in PA. And yes continued use did end up clogging the gas tube system. This was a 1:9 barrel used for speed shooting at 35y and under so no idea about 50y accuracy. Best off with a 1:16 dedicated AR .22LR barrel. I ended up getting the barrel adapter so I could use the CMMG kit as the BCG in my dedicated AR-22 using a Taccom barrel. Much more accurate.
     

    MifflinKid

    Member
    Dec 30, 2010
    37
    Howard County
    I used one in my Bushmaster A3. It was a great shooter with CCI .22 Tactical ammunition using Black Dog Machine magazines. With a Burris rimfire scope on the rifle I could usually keep a 1 1/2" to 2" ten shot group at 50 yards bench rested. That was several years ago before I had intra ocular lens transplants in my eyes. My two 20-something and 30-something nephews could usually shoot 1" to 1 1/2" at 50 yards bench rested.

    I haven't used it in several years as I built a dedicated .22 LR AR in 2013.

    I was happy with it and would recommend one if you don't want to buy a purpose made .22 AR or a .22 LR AR upper. One thing you have to remember is to thoroughly clean the barrel and gas tube when you change from shooting .22 LR to .223 ammunition.
     
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    erwos

    The Hebrew Hammer
    MDS Supporter
    Mar 25, 2009
    13,860
    Rockville, MD
    I love the CMMG system, but like others, would recommend a dedicated 22lr upper to avoid gas and barrel twist issues.
     

    rob-cubed

    In need of moderation
    Sep 24, 2009
    5,387
    Holding the line in Baltimore
    Get a dedicated upper. Not cheap, but worth it in the long run.

    I had a Ceiner adapter for a while, all of the .22 conversion kits out there are based on the same basic design. It works pretty well but in the end a dedicated barrel is going to get you better accuracy and you won't have to worry about gumming up the gas system.
     

    Nanook

    F-notso-NG-anymore
    Ammo is key for reliability and accuracy. Golden Bullsh*ts ignite much slower than Win red box stuff. FTF and FTE using that crap will kill your fun level, save that for your bolt guns or pistols. Some folks don't recommend it but after I'll shoot a bunch with the adapters, I'll blast out the gas tube with compressed solvent and immediately run a bore-snake. A few .223 to finish pushing more crap out of the tube before it cakes up in there too bad.

    Lube the heck out of the adapter as well with a light oil - I'm partial to synthetic motor oil but YMMV.

    Like any other .22, some brands/runs will perform differently in every different gun you run. If you can't/won't do a dedicated upper, play around until it does close to what you want it to.
     

    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,257
    HoCo
    Picked the CMMG kit up in DE at the Christiana Cabelas. They have them there on the rack. Took to the indoor range today which is what this was intended for.
    25 yards/75ft is all the indoor range goes to, so I shot it there. My AR is very light, I think 6.5lbs I recall. Handle and peep sights. Peeps are hard to see inside so flipped up the larger aperture. Shot it offhand after adjusting the rear sight. I only used copper coated bullets on it and shot Minimags and Winchester 333 through it. Not a single problem with the conversion kit. This is a fast 1:7 twist barrel so the accuracy is just fine for what I'm doing with it.
    The magazine gets rather difficult to load past 20 rounds, spring get tight and the rim of the round rolls off and you have to push it down some yourself to feed the bullet in. Last bolt hold open is only when the mag is in, so the AR's bolt hold open is moot with this adapter. Pull the mag and the bolt closes.

    This is 40 rounds, 25 yards offhand.
     

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    rob-cubed

    In need of moderation
    Sep 24, 2009
    5,387
    Holding the line in Baltimore
    Impressive! So I take it you're happy? :D

    You can buy a LRBHO kit for the CMMG... but IMO it causes more problems than it solves. A guy with one at an Appleseed had some pretty continual issues with it either not working, or working when it shouldn't. Maybe he wasn't the best test case in a sample size of 1 but it convinced me it's not worth it, especially if you don't have a dedicated .22 upper.
     

    rdc

    Ultimate Member
    Dec 3, 2010
    3,690
    Middlefingurton
    Impressive! So I take it you're happy? :D

    You can buy a LRBHO kit for the CMMG... but IMO it causes more problems than it solves. A guy with one at an Appleseed had some pretty continual issues with it either not working, or working when it shouldn't. Maybe he wasn't the best test case in a sample size of 1 but it convinced me it's not worth it, especially if you don't have a dedicated .22 upper.

    I have the BHO on my dedicated CMMG upper. It doesn't work with 99% of mags so it is only useful for locking it open when the range is cold. I has had to modify it heavily for it not to cause problems. I wouldn't recommend it unless you are REALLY dead set on having it and are willing to tinker.
     

    photoracer

    Competition Shooter
    Oct 22, 2010
    3,318
    West Virginia
    Best ammo I have used in a tactical .22 for functionality is CCI-AR Tactical. I use it in my 10/22 and Rem 597 also. Feeds really well in single stack high cap mags due to the narrower bullet profile (same bullet as CCI-SV but copper washed).
     

    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,257
    HoCo
    Yes, I am happy.
    BTW, the Minimags were the 40gr ones just like the AR Tactical.
    I'm NEVER had a 22 that did not like CCI.
    Their brass is just better design. the rim lip is flat further away from the center than any other brand. Just more friendly to the ejector.
     

    atblis

    Ultimate Member
    May 23, 2010
    2,008
    I put together a dedictated 22 lr AR15 for Appleseed.

    My thoughts
    -A dedicated barrel is a must. TACCOM has them for ~$100
    - The TACCOM reliability kit is spiffy.
    -I highly recommend the Better-Mag adapter and the S&W 15-22 magazines. The adapter needs to be fixed to the lower receiver in the correct spot. Mine will ride up and eventually lock the bolt up if installed per the instructions. JB weld for the win. The adapter makes the bolt catch work and fits the S&W mags.
    -The S&W mags are the best AR 22lr mags IMO.
    -When it was all said and done, I had a $2500 22 lr AR15. :)

    20150201_171116.jpg
     

    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,257
    HoCo
    Range Report on my CMMG.
    Reminder, I'm shooting a 1:7 twist 15.something barrel with a pinned/welded brake.
    25yrds offhand indoors.
    Shot Winchester copper jacketed HP 333 or 555 box). I was going to shoot some golden bullets cause they seem to be the worse jacketed ammo I have. I forgot to bring them.
    48 out of 50 into a 5" circle @ 25yards offhand so I'm happy with that.
    I still have yet to test @ 50 yards w/ my 1:9 barrel and scope cause AGC is doing lead reclamation during the week when I shoot there.
    So far, I have yet to have any hiccup out of it.

    No plans for a dedicated barrel at this time for me. We'll see when the round count gets higher. I'm at 200 right now.
     

    embermage

    Active Member
    Sep 20, 2013
    747
    Rising Sun
    I put together a dedictated 22 lr AR15 for Appleseed.

    My thoughts
    -A dedicated barrel is a must. TACCOM has them for ~$100
    - The TACCOM reliability kit is spiffy.
    -I highly recommend the Better-Mag adapter and the S&W 15-22 magazines. The adapter needs to be fixed to the lower receiver in the correct spot. Mine will ride up and eventually lock the bolt up if installed per the instructions. JB weld for the win. The adapter makes the bolt catch work and fits the S&W mags.
    -The S&W mags are the best AR 22lr mags IMO.
    -When it was all said and done, I had a $2500 22 lr AR15. :)

    20150201_171116.jpg

    I've got to second the Better-Mag adapter idea! Got one for my .22 build, works great with the S&W magazines, to include the Black Dog drum.
     

    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,257
    HoCo
    ok, I had it out at 50 yards. This is in a fast 1:7 twist barrel and iron sights. From bag it was about 3" groups with random fliers. My plinking ammo in 223 for this AR is about 2" groups with those sights on bags. So this was nearly perfect for offhand shooting. Interestingly enough, point of impact was within inches of 223 at 50 yards.

    1st pic is 223,
    2nd pic is the 22LR using the conversion kit.

    Both offhand @ 50 yards.


    .
     

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    dontpanic

    Ultimate Member
    Jul 7, 2013
    6,625
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