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CMMG .22LR exchange kit

B191299

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With the crazy price of .223 and .556 ammo these days , I started looking into alternatives for getting the ARs to the range. I came across the CMMG .22 exchange kit and tried it out today. I brought 3 ARs and used Aguila .22 Super Extra ammo. They ran fine and I had no real problems other than the optics, being zeroed for .556 at 50 yds, were off for .22 at 50 '. I found it much better than using my M&P15-22, as you can manipulate the controls , and feel the weight of an actual AR. I would recommend this kit, and although it is around $200, it won't take long to pay for itself in ammo savings.
 

grey

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With the crazy price of .223 and .556 ammo these days , I started looking into alternatives for getting the ARs to the range. I came across the CMMG .22 exchange kit and tried it out today. I brought 3 ARs and used Aguila .22 Super Extra ammo. They ran fine and I had no real problems other than the optics, being zeroed for .556 at 50 yds, were off for .22 at 50 '. I found it much better than using my M&P15-22, as you can manipulate the controls , and feel the weight of an actual AR. I would recommend this kit, and although it is around $200, it won't take long to pay for itself in ammo savings.
How was accuracy out of the .223 barrel?
 

pinefd

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Hah! Mine was just shipped today! Can't wait to get it and try it out. One of the benefits for me in getting this kit...besides the cost savings for the ammo...is the ability to be able to use it at the indoor ranges at the two clubs I belong to.


Frank
 

Rocco Mozz

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Bought one months ago mid pandemic (late summer) and loved it. I almost bought a complete 22 LR dedicated upper but I ended up rolling with this and I like it a lot more than the idea of having a complete upper for 22 LR because I can always swap back in the original bolt and then its a complete AR build I know and am familiar with and I can always just pop the bolt in and new mags and bam I’m back to a training setup.

As far as accuracy I haven’t taken it out past 25 yards. So at short effective distances it has been exactly what I was looking for.
 

mac1911

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Can someone break this down for me ? The kit appears to just be a bolt and a mag. So everything else just works? LRBHO? Mag release? Barrel???
LRBHO ? Maybe some do some dont?
Its a bolt with a “chamber “ adapter
They work , accuracy well dont hold your expectations to high.
 

mac1911

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I'm curious about the accuracy out to 200.
I did not get good enough accuracy to bother going out to 200 yards with my CMMG I ran mine through a STAG carbine with a 1-9 twist , 100 yards was laughable. I wasted 35 rounds of Tenex on the conversion kit. After that I only used it with cheap bulk ammo until I sold it to my friend.
I bought a Tacsol dedicated 22lr upper and it shoots very well , 200 yards no wind with SK standard plus or better anmo and it can hold the 10 ring of a SR target or about 3 moa, on average holding the 9 ring is a good day. I have pulled several MOA groups with better match ammo but not consistently at distance.
 

pinefd

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Having just received my CMMG conversion kit, I just tried installing it, and can't close the receiver back up afterwards...there's still around a quarter of an inch gap. It seems to fit and seat ok otherwise. Tried installing it on a brand new Colt M4 EPR. Anyone else have this problem?

Frank
 

PappyM3

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Having just received my CMMG conversion kit, I just tried installing it, and can't close the receiver back up afterwards...there's still around a quarter of an inch gap. It seems to fit and seat ok otherwise. Tried installing it on a brand new Colt M4 EPR. Anyone else have this problem?

Frank
Hmm, no. I haven’t experienced that.
 

Palladin

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I grabbed one last summer on sale for $149, with three standard cap mags. I run it in my S&W M&P, works flawlessly. it's a lot of fun.
Simply remove your BCG, drop in the CMMG, change mags and you're good to go
 

cathouse01

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The CMMG is s simple blow back bolt with a 223 chamber adapter on the end of it. I’ve had mine for a couple of years. I consider it only good for tin can plinking at 25-50 yards. One thing to watch out for is cheap lubricated lead .22 LR ammo can fowl the gas port on your barrel.
 

northny

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Having just received my CMMG conversion kit, I just tried installing it, and can't close the receiver back up afterwards...there's still around a quarter of an inch gap. It seems to fit and seat ok otherwise. Tried installing it on a brand new Colt M4 EPR. Anyone else have this problem?

Frank
when you insert CMMG adapter into upper, it should go flush with back of upper just like a BCG. If it doesn’t go flush look to see if chamber adapter is installed correctly. Chamber adapter looks like .223 case. They are removable but be gentle, you can bend side rails. You can google removal and cleaning. I assume rifle has clean chamber.

If adapter does go flush with back of upper and upper won’t close on lower, then perhaps interface with hammer? Have you tried it with hammer both cocked and uncocked?
 

allen-1

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I'm curious about the accuracy out to 200.
I bought the entire upper from CMMG, which includes a barrel with a twist rate designed for .22. I had excellent accuracy at 100 yards, never shot it further than that.

Traded it a couple of months ago for some parts to a buddy who was looking for a .22 for his son.
 

pinefd

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If adapter does go flush with back of upper and upper won’t close on lower, then perhaps interface with hammer? Have you tried it with hammer both cocked and uncocked?

Thanks. This was exactly the issue...the hammer (I'm brand new to the AR platform). Once I figured that out, I was able to close it up easily...and off to the range I go! I'll report back later on how the range trip went.


Frank
 

northny

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Keep in mind if you have the conversion kit kit with the .223 adapter, and you want to go to a dedicated .22 rim fire dedicated upper, it’s pretty simple. Buy a .22 rim fire AR barrel with the adapter collar for the barrel. (I bought my last one from CMMG, it was accurate enough to shoot 240 out of 250 at an Appleseed). The adapter collar for the barrel replaces the .223 adapter on the conversion kit. Then just build an upper with the .22 rim fire barrel. upper doesn’t need gas block or tube.
 

silversquirrel

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This thread got me interested in checking one of the these out. I had an original colt 22 kit, but sold it years ago. Just ordered the CMMG kit from Primary Arms. I like that it comes with 3 mags. The Colt kit only came with one, and spares were impossible to find at the time (late 90s).
The colt did pretty well for accuracy in my preban colt 16" 1/7 bbl, with sv, but only ran reliably with minimags, not the sv, and the minimags caused fliers and shitty groups compared to sv.
 

pinefd

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I had, what I would consider, a pretty good day at the range with this yesterday. I just used it at my club's 50' indoor range, so I could get used to the brand new gun, see how the conversion kit worked and to sight in the new red/green dot. Although they recommend shooting 36 grain plated ammo (Federal CPHP is the recommended ammo), the closest thing I had was 40 grain CCI Mini Mags. They also recommend a round hammer versus a notched hammer, for reliability reasons, but since my Colt came with a notched hammer, I wasn't going to swap it out just for this kit. I shot 100 rounds of the Mini Mags and everything worked flawlessly; and after getting it sighted in, it was very accurate, as you would expect at this distance.

For the last 20 rounds of the day, I figured I'd try some cheaper ammo, and went with Federal 40 grain non-plated blue box ammo. I only put 10 rounds into the mag at a time. With the first shot out of both mags, I experienced a slam fire, but it ran fine with the remainder of each of the mags. So I'm not sure what would have caused the slam fire, but I'm thinking I'll stick with the Mini Mags going forward, unless I'm able to find some 36 grain plated ammo. I suppose that the notched hammer might have had something to do with the slam fire, or the cheaper ammo...or possibly the magazines themselves, which are not a tight fit in the AR.

And speaking of the mags not being a tight fit, when researching the potential cause of the slam fire, I came across a lot of discussion about the loose fitting CMMG mags, with many people saying not to use them. A lot of people recommended these mags, so I ordered a couple of them last night (these are 25 round mags, so not available to those in MA, of course...although they do come in 10 round versions as well): Black Dog Machine Sonic X Conversion Mag Nylon Feed Lips AR-15 CMMG

In the next day or two, I hope to get out again and try this conversion kit in my new AR pistol, although I know that there's very mixed feelings about how well this kit works in a pistol. But it should be fun trying it out anyway. At least the pistol has a round hammer, so that should eliminate that as a possible cause of any reliability problems.

I'll keep you posted with any additional developments!


Frank
 

pinefd

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I just realized that never updated this thread after my previous post. I did make it to the range with my AR pistol, and the conversion kit worked flawlessly (with no slam fires). I shot 100 rounds of the Mini Mags, and had a lot of fun doing it.

I mentioned above that I ordered some Black Dog Machine conversion mags because the original CMMG mags were a loose fit. I did receive the new mags from BDM, and got a chance to try them out. I actually didn't really find them to be much, if any tighter fitting than the CMMG mags. But I didn't have any problems feeding from either type.


Frank
 

paul73

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Tried this out on sunday. Works like a charm. Highly recommended. So much fun!

Dead on. No sight adjustment needed. Just swap the BCG and pew pew
so, a 'bravo' kit is just an BCG, and there is also an 'echo' kit with a handle - why is so?
 
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