Anybody use one? What are your thoughts about brands. Which work and which are junk?

I have a Ceiner kit for my Colt A2 and it works just fine.
Bought it probably 20 years ago. You just have to keep
"everything" clean which is a job considering how dirty
most .22 rimfire rounds are.
Hope this helps.

Chuck

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They hold no Quarter

I use a dedicated upper from CMMG. It shoots well, but there are a few things I don't like, such as the last shot bolt hold open only works when a magazine is in the gun. When you drop the empty magazine, the bolt goes forward, so you have to pull back on the charging handle when you insert a new magazine. But the operation of the bolt and feeding works really well.

Thanks, how's the accuracy?

With the dedicated upper, accuracy is very good, as the twist rate is the proper twist for the .22lr bullet. I shoot mine at 25 yards, and hit the 1" round shoot-n-c stickers, with iron sites.

A dedicated upper with the correct twist is the best way to go. That said it does require purchase of an additional sighting system if you're not using iron sights. For occasional plinking use the CMMG unit works fine for me. I also use the CMMG unit if I have more than one person shooting. I have and use both.

That's what I was thinking, twist rates.
Don't have the bucks for an upper but hoped the kit would give ok accuracy to 25-50yds.
Will they keep it within an inch or two at those ranges?

You'd probably be satisfied with the accuracy. ARs in 223 are available with different twists. If you is 9 to 1 you're probably better off than with 7 to 1. :-)

The CMMG units run $200 or so as I recall and a new upper would be double that or more I think.

Mine is 1/9 so maybe it will hit an empty can at those ranges. That will be ok just to get the trigger time.

Aguila makes some super subsonic 22 rounds



With a 38 gr bullet, and I thought I had some with really long bullets that were close to 60 gr but I might be misremembering. Maybe a longer heavier bullet would stabilize better with the faster AR twist?

aguila makes a 60 gr. they call a sniper load. i have some subsonic ammo by aguila but a different style b ox.

Get a Better Mag from Boonie Packer. They allow you to use the S&W MP 15-22 magazines and lock open the bolt just like the full caliber guns.

I had a Ceiner kit for a Century C15A1 I had. The C15A1 is assembled from surplus M16A1 parts on a new AR15 lower with a new barrel. The Ceiner functioned 100% with all ammo I had- thunderbolts, automatch, and mini mags. Accuracy was about the same at 25-50 yards as shooting .223/5.56 The only difference was that the .22lr had a different POI than the .223/5.56. If I recall correctly the .22lr POI is 3 or so inches higher than .233/5.56.

I sold both the C15A1 and the Ceiner last year during the panic when someone made a great offer. Selling the C15A1 funded a new Browning 20ga O/U. Couldn't pass that one up. Now I have a Sport, which is a much better AR than the C15 anyway

A conversion kit will save you $200 plus over a dedicated upper. With the lack of .22lr, I'm not sure I'd invest in a dedicated upper right now. You're almost better off financially to reload .223.