HD Tactical

CMMG Conversion Kit For converting AR15 to .22lr

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  • APT Synthesist

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    Hello There

    I would like to generate some discussion on the CMMG .22lr conversion kit.

    I bought one of these and ran it in an A2 clone and a heavily updated/modified S&W M&P15 build and had a lot of jamming issues so I sat it aside for like a year.

    Recently I got a wild hair and tried it again in my Daniel Defense M4A1 and it ran flawlessly, I even took it to a training course and probably have ran about 1000 ends through it without issue at this point.

    I do run a mag of 5.56 through it every few hundred rounds and clean it thoroughly.

    I have two camps of people, both much more experienced, advising on this....one camp says this is terrible and I will foul out/ruin gas system, another camp that seems to indicate it will be fine as ling as I continue regiment of blowing it out with full power ammo occasionally and cleaning.

    Thoughts?
     

    Anangrypasta

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    I've put thousands on thousands of rounds through my ARs with the CMMG and, far as I can tell, ive seen no issues at all. Barrel and gas system cleans out the moment you fire a 556.

    One of my rifles has a slightly overtight chamber, so occasionally a steel 223 case gets stuck after using the CMMG. My solution is to use brass for the cleaning mag, which has no issues.

    My main gun that the CMMG is used in is a retro build using a SP1 Colt upper with a 20" 1:12 barrel and rifle length gas. I've done several thousand rounds of 22 in that one and there is no perceived unusual wear on the gas system. Shoots perfect once you throw a 556 in there. Side note, that rifle also has a notched hammer which CMMG advises against due to reliability issues. Ironically, it's been the most reliable of my ARs using the kit lol.

    I'm not a gunsmith nor an armorer by any means, but my personal experience says these things are fine! Just run a couple rounds of 556 through it here and there during the same range trip if you are going big.
     

    .22 cents

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    I spray non chlorinated brake cleaner (with straw) in the gas tube followed by a blast of air from the air compressor but then im weird af too :)…any soot spills into the bore and then I clean the bore. Easy. Never had a gas problem. Only at Taco Bell.
     

    Viper0hr

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    I have a CMMG conversion kit I used for a few years and then 2 years ago purchased a CMMG .22 dedicated upper. Both run great, very few issues other than normal .22LR ones.
    Just clean them and the gun as you would when dirty, and if needed lightly oil the main kit pieces/rails themselves.

    There have been versions of this style .22 conversion for years, including ones used by the military, and they have just gotten cheaper and better as time has gone by. i'd say there's no need to worry about issues so long as you maintain your firearms and check the kit every once and a while for wear.
    I was able to buy my 3 25rnd mag kit for $100 on sale, normally the cheapest I've seen them for is $150-160, for that price it's a no brainer for a AR15 owner and I tell everyone I know they should get one, even if they "don't like .22" for some reason lmao.

    edit:
    The one thing I would look for in problems is ammo type, hollowpoint/low power ammo may cause realiability issues feeding, but that's with any ammo type really, and IF you end up with a funky mag you may need a new one, but the mags tend to be under $20 for a 25rnd one and on sale (Black Friday especially) I've seen them as low as $10.
     

    Viper0hr

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    if anyone wants to sell one on the cheap, I'm interested! I want to build a star wars blaster..
    Keep an eye out for BF sales online, I bought mine for $100 years ago, only time I ever saw them that low, but they go on sale for as low as $150 for the one with 3 25 rnd mags. Anything sub $150 is a deal imo.
     

    jettjon

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    CMMG / Black Dog fan here, I have a dedicated S&W M&P 15 that I only run .22's on. I have slightly modded the charging handle as others have mentioned to prevent the occasional stuck round. Really you can get away with just a bead of caulk or something in the CH to fill the dead space. Other than that my main problem has been with a couple of the Black Dog magazines breaking apart. Solution, buy more mags.
     

    ParrishGhost

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    Reviving this as I've bene using one at my local range due to their rules on no rifle calibers allowed. I'm amazed at how accurate it is with some AE 40 gr I've had sitting around. I tried newer CCI that was only 32 gr and it shot terribly. This is my 1st day at the range with my new build. 18 yds off a rest and standing. I may buy my own to use at the outdoor range.
     

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    RHINOWSO

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    I owned one for a couple years, not a bad piece of kit but the different twist rate of a standard AR15 means the rounds will hit lower POI. Obviously you can adjust your optic / sights to compensate.

    In the end I just didn't use it that much and sold it. I have a S&W MP-15/22, which is also nice but it doesn't see much use either. The CZ bolt guns and Winchester 9422s, plus the suppressed pistols get most of the 22 these days.

    But it's a quality piece of kit so if it works for you, carry on!
     

    jettjon

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    I owned one for a couple years, not a bad piece of kit but the different twist rate of a standard AR15 means the rounds will hit lower POI. Obviously you can adjust your optic / sights to compensate.

    In the end I just didn't use it that much and sold it. I have a S&W MP-15/22, which is also nice but it doesn't see much use either. The CZ bolt guns and Winchester 9422s, plus the suppressed pistols get most of the 22 these days.

    But it's a quality piece of kit so if it works for you, carry on!
    What's REALLY fun is to add a .22 cal suppressor. Way cheaper than 5.56.
     
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