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Always looking for a way to get more bang for the buck, I decided to try one of the .22 long-rifle conversion kits for our police AR-15 patrol rifles.

http://cmmginc.secure-mall.com/item/CMMG-.22-Conversion-Kit-with-Magazine-1343

Got the kit, which is simply a drop-in replacement for the bolt-carrier group, and a new magazine, for $169. It very simply just dropped in, replacing the bolt-carrier group. The magazine has a couple of "bumps" molded in that can be filed down for a precise fit to individual guns, but as yet I haven't done that and the mag works just fine in several different rifles. It's a snug fit though.

For ammo I used CCI mini-mag 40 grain .22 long-rifle, a plated bullet.

The first impression from every shooter so far has been a huge grin! ;D Next is a realization that the rifle, fitted with this conversion kit, is both accurate and reliable. All our shooting so far has been at 50 yards and in, as appropriate. Accuracy appears to be on a par with that we're getting from 55 gr FMJ 5.56 ammo, and we haven't had to adjust the sights either.

What this means to me as a trainer is that I can get the guys about four times as much trigger time for the same amount of money. We can do the majority of our practice with inexpensive .22 long rifle ammo, then switch to the 5.56 mm ammo for qualification and a little more training where the muzzle blast of a full power cartridge is an important aspect of the training.

Marksmanship though - we're going for the .22's all the way. At this point I've got us three of the conversion kits, and am looking for three more. As a bonus, I was able to swap seized guns for the conversion kits and ammo.

If you've got an AR-15, consider the CMMG kit as a way to reduce training costs.

Guy
 

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$169 sure beats $500 or more for an AR-15 lookalike! Is that the LE price, or retail?

And thank you for mentioning the vendor by name. There are a lot of uppers and conversion kits on the market, and some of them aren't worth a thimble-full of fermented camel vomit. ;)
 

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Sweet! Now I won't have to forge any more "department" letterhead! ::) ;) :eek:
 

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I tried one in mine and was disappointed in the accuracy (it was a CMMG). While it was fair I suppose; the difference from how it shot with 5.56 ammo was enough that it pretty well killed my desire for one. Differences in our barrels I guess.
 

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Maybe a difference in requirements. I don't need pinpoint accuracy.

Have six of the kits now. Was just out on the police range with the officers yesterday. One portion of our training was simply working through the basic shooting positions, establishing natural point of aim, working on breathing, sight picture, trigger control, from prone, sitting, kneeling and standing. We did a LOT of that training at modest range with the .22 CMMG kits installed in both Colt and Rock River 16" AR-15's. The Rock River produced really sweet accuracy, but our older Colts also did decently well.

Pinpoint accuracy isn't why I'm buying/using these kits. "Good enough" accuracy, with good consistency & reliability, is plenty. I wanted a training tool that allows my officers more trigger time with their "patrol rifles." The accuracy is pretty good though, especially with that Rock River. I'd take it squirrel hunting!

The six officers going through rifle training yesterday hadn't used the .22 conversion kits before and came away with big grins. We shot a fair bit of .223, and a mess of .22 long rifle mini mags. Good fun, and worthwhile training.

Regards, Guy
 

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Guy,

Have you seen any indication the 22LR's are clogging up the gas system in your rifles?

I've read where this can be a problem, so I was shopping for a complete dedicated upper. There are many 22LR uppers
available........As always, I think most of the time, you get what you pay for..............
Some of the offerings leave me less than intetested. and one,........Compass Lake looks to be a Target/Match quality unit. A fellow competitor has one, and claims 1MOA @ 100 yards with good ammo. I have not shot his upper, nor have I seen him shoot it, but he's the type of shooter that would NOT keep it, if he wasn't pleased with it..........It IS expensive though..........

Tom
 

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My son and I use these conversion kits in our AR's.

Accuracy is good but ours are not a one holer at 50 yards by any means. Consider that most 22LR runs a 1/16 twist whereas most modern AR's have a 1/9 or 1/7 twist. It would still be minute of squirrel at 35-40 yards though. We have had the best results with the Federal 36 grain bulk paks forund at Wal Mart. The Feds seem to have a little more pointed bullet that feeds more reliably in our rifles.

Still it's cheap trigger time.

As for the gas tube, we always run a few rounds of 223/5.56 thru the rifle at the end of the session. 55K PSI will clean out any gunk that might be in the gas tube.
 

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7/20/11

I have a CMMG conversion kit which I use with a dedicated Stag upper. The lower is Stag also. I use CCI Mini-Mags- 40gr and solid nose/copper plated.

The .22LR unit is very accurate when its working corectly.

The first time I used it, I got about 6 to 9 rounds before there was a failure to eject. Cleared the empty case and resumed firing and it happened again and again and again.

Got it home and started doing some research that included a call to CMMG. The CMMG technical person was extremely helpful. He told me to "buff" the bullet end of the upper's chamber insert with a .22LR cleaning brush and a drill. He was very clear that I should only "buff" until the unit gets warm.

Went out to the range and the results were worse; got to 4 or 5 shots before a failure to eject occurred.

Any one out there in Marlinland have any ideas as to what the problem may be and as to what to do next?

I will certainly appreciate any feedback and thanks !!
 

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I have had the best luck with the Federal bulk paks that can be purchased at Wal Mart. It seems to have a more pointed bullet to aid in feeding.

You might try some of those and see if it helps your feeding problems.
 
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