CMMG 22lr Conversion Questions

[cfts0914]

I shoot NRA Highpower XTC matches with a .223 match rifle and am looking for a good trainer setup. I looked at the Crosman MAR177 but its pricey and almost impossible to find. I know I can build a dedicated 22lr upper but I really don't have the budget for that. The next best option, as far as I know, is the CMMG .22lr conversion kit. I would also buy a Smith & Wesson 10 rd magazine to mimic the proper mag size.
Questions:

1. I have a 1-7 twist which I know is way too fast for .22lr bullets. Could I expect more accuracy with heavier 45gn subs? The 60gn Aguilas are too pricey.
2. What effect could I expect on barrel life? I would imagine very little, especially with subs, but I don't want to be unpleasantly surprised.

For reference I have a Compass Lake 26" upper with a 1-7 Douglas. I am also aware of the nastiness of the 22lr rounds and that I need to occasionally shoot .223 rounds to keep the gas system clean.

 

[kzin]

You can't expect good accuracy period.
Twist is the least of it.
Bore too big.
Jump from chamber to rifling.
For HP prone level accuracy you need a dedicated upper.

 

[jepp2]

and am looking for a good trainer setup.

What kind of 22 LR accuracy are you looking for to be meaningful training?

I had the CMMG 22 conversion unit, used it once then sold it. Just not my idea of useful. I bought a dedicated CMMG 22 LR upper. I sat in the box for a couple of years - I never fired it. And sold it to someone that it would do what they wanted.

If you are looking for any kind of accuracy to be useful for training, you will need an accurate 22 and some ammo capable of shooting quality groups. That means the ammo is going to run $7 per box or more.

 

[C.E.Smith043]

You can't expect good accuracy period.
Twist is the least of it.
Bore too big.
Jump from chamber to rifling.
For HP prone level accuracy you need a dedicated upper.

This comment is spot on ^^^

 

[cfts0914]

I am primarily wanting it for offhand practice. The black on a HP target is about 6 MOA. I could back the target up to 25 yards or less to account for the inaccuracy. Any thoughts on barrel life?

 

[troupe]

The CMMG 22 conversion will never be able to give you the accuracy that you are looking for. CMMG basic conversion was for a cheaper way to fire a AR style rifle. If you get the conversion that does not have the 223 round built into it and get the bolt setup with a actual 22 barrel will be better. Still cheaper than a custom top end.

Your rifle that you shoot in competition needs to be duplicated for the balance and feel, which could be very expensive.

 

[cfts0914]

Much appreciated. Looks like i may end up getting the CMMG bolt and 16.1" barrel 22lr combo and pairing it with a cheap upper reciever and just add whatever weight necessary to match my .223.

 

[Warren Dean]

I am primarily wanting it for offhand practice. The black on a HP target is about 6 MOA. I could back the target up to 25 yards or less to account for the inaccuracy. Any thoughts on barrel life?

You'll never shoot out a 22 rimfire barrel in your lifetime.

 

[kzin]

If your offhand is weak enough that you need practice hitting the black then it may be good enough..
In the long run even the inexpensive dedicated will be a better purchase.

It's also possible to use most of the bolt and just change the chamber part between dedicated and 223.
IF somebody will sell you the chamber adapter.

Possibly you could put in bulk work with the dedicated and tune up a bit with the competition upper.

 

[chromatica]

I did a deep dive into this subject some years ago. 22LR accuracy is not the only problem. 22LR is a very dirty round. This can cause big reliability problems when you want to remove your conversion bolt and start .223 again. A number of shooters went to dedicated uppers because of all the problems they had with the conversion kits.

 

[bpm990d]

You might not like this answer, but I would skip a .22LR. I have a dedicated .22LR trainer with a WOA scope and the whole 9 yards. It's plenty accurate, but I don't really like shooting it. It's not the same as shooting centerfire and I don't think I get a lot of training value out of it.

I think most would be better served from a training standpoint with a real .22 target rifle or even better a .177 airgun. When we shoot during the winter, I let other peeps borrow my AR trainer and I shoot my Anschutz Air Rifle.

 

[cbailey1956]

I have a cmmg upper and it will hold 1- 2 inches at 50 yds. put a beyer barrel on it and it will do 3/4 inch at 50 yards. I have used it at steel challenge matches and its reliable and accurate. use cci tactical rounds and it works. fun and good training. use a cheap upper and match the rail with your 223, could weight it to match the feel. just saying, but you have to put a few dollars in it. cost and benefits only for you to decide. good for new shooter to start out on also. my grandkids love it.

 

[6fatrat]

I live in northern Michigan and have to train indoors 4+ months a year.
I tried the conversion kits, trying different ammo i was able to hold the 9 ring on the A-17 target.
I bought a used dedicated upper from a Texas HP shooter, it shoots 1 hole all day long at 50'.
Scandale in Penn. was the smith that made mine, he used some parts from the CMMG kit.
I cut the CMMG mag shorter to the same length as my 20 rd. 5.56 mags
You need accurate feed back from your training sessions, buy once cry once.
Steve Bair







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