I just learned how easy these conversions are, and now I want to buy one for my AR.

The brand I see most often is CMMG, for a product specifically named, 22LR AR Conversion kit Bravo. They seem to run around $150.

Is the CMMG conversion a good choice? Are there better choices for this sort of conversion kit? I'm not looking to buy a complete upper or a dedicated .22 AR.

Thanks!

Been very satisfied with my CMMG conversion kit that I installed in an AR pistol.  Topping it all off with a Dead Air Mask made it even more fun and very quiet.

Do eeet!

Thanks! Maybe I'll pick up a suppressor someday too.

If you not going dedicated....then CMMG is the way to go for sure.

The twist of your 5.56/223 barrel makes a difference in potential accuracy of 22 rimfire ammo.  I’ve had better overall accuracy with 1:9 twist and less common 1:12 twist.   All the 5.56/223 barrels produce fliers with 22 rimfire bullets.   Many 5.56/223 barrels will produce different accuracy with different ammo.  For shooting steel plates and CQB drills the 1:7 twist are fine.   Shooting groups at 50 yards on paper targets will usually produce erratic accuracy because of the fliers.  I’ve gotten some of my best accuracy with high velocity plated bullets like Federal 38 & 40 grain game shock, 36 grain Federal  550 bulk, 40 grain Mini Mags and Aguila plated 40 grain Super Extra.  I also get decent accuracy with CCI Blazer and CCI standard velocity.

Much appreciated.

Thanks. I've been wondering about the rifling differences. My rifle has a 1:7 twist, but I'm not really looking for great accuracy. As you say, plates and CQB drills and plinking is about all I will likely do with the conversion. Do you have experience with the CMMG?

Here is a test I posted in the rimfire and pistol section here on ARF.com.  My original post is archived but here is the same test on a different site.  There are pictures of targets shot using a conversion in 1:7 twist at 50 yards.  The cheapest place I’ve found for CMMG 22 conversion is right to bear.


http://www.rimfirecentral.com/forums/showthread.php?t=754849&highlight=22+conversion+test



https://www.righttobear.com/CMMG-drop-in-22-conversion-kit-w-25-Round-Mag-Bravo-SS-s/1873.htm

I have the CMMG 22 conversion and have been very happy with it. It's great for plinking and plates but not going to win any accuracy awards.

I'd be happy with the groups you show for the PSA 1:7. The Aguila Super Extra 40 grain plated RN High Velocity seems to be one of the better choices, which is great because I see those available most of the time.

I shoot a lot with a friend who has an M&P 15-22. There is a company that makes an adapter so that the CMMG conversion is able to take the S&W magazines. Are you familiar with this adapter?

Thanks, sounds like what I'm looking for. Reliability is more important to me than accuracy for this conversion.

Damn you. You just cost me money. Ordered the BCG with 25rd mag. 

Now, to decide on barrel length. I have a handful of SBR lowers sitting in the safe. But, already have a suppressed shorty 10/22 takedown. Part of me wants to clone my 16" 3gun rifle to make it a cheap trainer. I also wouldn't be hunting down subsonic ammo for the longer one...

These first world issues have really got me down. 

Edit: Anyone know how well the SD3G trigger runs with these conversion kits?

Here is thread about Geissele SD3G trigger (with conversions & dedicated uppers)  in the rimfire and pistol AR-15 forum.  



https://www.ar15.com/forums/ar-15/CMMG-22lr-bolt-with-S3G-trigger-/15-718248/

There is an adapter to use S&W 15-22 mags with CMMG conversions Boonie Packer Better Mag Adapter.  The BMA can be purchased from several retailers like Brownell’s.

https://www.brownells.com/rifle-parts/receiver-parts/caliber-conversion-kits/ar-15-m16-better-mag-s-w-m-p-15-22-magazine-conversion-adapter-prod56474.aspx

Or buy a $300 22lr Upper from PSA  Get that 1/16 twist and an optic dialed in for that upper.

Yes, that is the adapter I was talking about, thanks. Have you tried it?

True, and I may do that one day, but I like the idea of practicing cheaply with the same exact upper and with the same optics and BUIS.

i've been very happy with a complete Tactical Solutions Kestral upper

it isn't cheap but you get what you pay for...

I was thinking about picking one of those up myself - I assume they go on a standard unmolested lower.  What do they take for magazines?

Just waiting for one more recommendation before I buy the CMMG conversion. Just one more...

I picked one up about 15 years ago, it was referee to a Ciener Kit, are they even still around anymore? I never had problems with it using the mags by Black Dog Machine. Are the new kits better?

No idea if they are better, but the gun dudes on Youtube seem to like the CMMG. Some people here too seem to like them.

I don’t think the current TACCOM 22 LR conversion kit works with the Better Mag Adapter.   TACCOM used to modify his bolt to work with the Better Mag Adapter but quit offereing the Service.  I’ve had a Ciener conversion since the late 90’s when the AWB was still in effect.  Other than breaking firing pins I’ve never had an issue with the Ciener.  I have two parkerized CMMG 22 LR bolts I now use with dedicated uppers.   I have no experience with a Target Master 22 conversion but it also appears to be a copy of the Atchisson/Ciener/CMMG conversion.   I don’t know if the BMA will work with the Target Master kit.   I know the Better Mag Adapter will not work with Tactical Solution, Nordic/JP/DPMS GII, ATI dedicated uppers,  M-261, Colt/DPMS G1 or Air Force 22 conversions.  


I have a lot of the BDM mags which I purchased prior to the release of the Better Mag Adapter and never felt a need to invest in S&W 15-22 mags since my BDM mags function great.   I never go to public range so a non functional bolt catch has never been an issue

Got one about a month ago, on sale at cabellas, for $170.

I have only ran CCI AR Tac's in it & it seems to work pretty decent in my 1/8 556 NATO stainless.

Instructions state cleaning your barrel every 500 rounds & to watch for build up in the gas system so run a few rounds of 556 through it after shooting 22lr to clean out the gas system.

Just make sure you lube it good.

& thanks for the mag adapter link. I have a few plinkerton mags from when I had a 15-22 laying around I'd like to be able to use. I tried them but the bolt hits the top of the mag. I did some measuring & it appears if I machine .100" of the top of the mag catch recess it should clear but I haven't tried it yet. Now I see another option.

You're welcome and thank you for my fifth recommendation. I'm going to buy it now.

I wondered about whether it would foul the barrel or anything like that. I suppose if it prematurely wore or damaged the barrel in any way, people would have said so.

Yeah it's lead fouling is why it says you should clean every 500 rnds or so. I'm guessing it's due to reduced velocity & thinner copper plating on the bullets...

Haven't done a lot of searching for info as to whether or not running 556 rounds every few hundred helps with that or not, but I did see it mentioned it helps keep the gas system a bit cleaner & may extend cleaning intervals.

I planned on tearing it back down to see how gunked up it is getting every 500 rnds, so that will be pretty soon.

Perhaps the guys that have used it for long periods can chime in.

Regular Black Dog Machine mags.

Here is the first review post Ive seen on PSA 22lr Upper

I wouldn't order one from him now, but like I said I got it 15 years, heck it was before Y2K now that I think about it.

Hopefully, VASCAR2 can tell us something about fouling and lead buildup. He seems to have a great deal of experience using these conversions.

Are BDM mags and CMMG mags compatible/interchangeable or are they different? Thanks.

Yes the CMMG and BDM are interchangeable in the sense they each work with the same bolt designs and uppers.  The polymers used in the bodies are different but both use a bolt hold open follower.   Once the last round is fired out of the mag the follower comes up blocking the bolt from closing on an empty chamber.   The BHO followers help the longevity of the firing pins and helps prevent dropping the hammer on an empty chamber.  I ruined a DPMS Gen 1 barrel from repeated hits on an empty chamber with 10 round factory DPMS mags.

Shooting 22 rimfire in an AR-15 is absolutely filthy.  Crud gets in the lower receiver and lead will build up on flash hiders or muzzle breaks.   I got to where I was shooting so much rimfire in my centerfire 5.56/223 AR-15 I bought dedicated rimfire uppers.   Plated rimfire high velocity ammo like Federal Bulk 36 grain, CCI Mini Mags and Agula Super Extra 40 grain plated don’t lead as bad as ammo like Remington Thunderbolts, WW Wildcats, Winchester Xperts.   I never noticed much leading in the barrel with the plated ammo but the gas port can plug with lead if you don’t occassionally shoot some centerfire ammo.

I normally shot 3-5 centerfire 223 55 grain FMJ after shooting 500 to 1000 plated 22 rimfire.   I always pulled a bore snake through my barrels three times before shooting centerfire ammo.   I never encountered any malfunctions with centerfire ammo or saw any indication in loss of accuracy when shooting centerfire after firing rimfire ammo.  

Most of my rimfire was shot in chrome moly 1:9 twist barrels but I did shoot a little rimfire through 1:8 twist SS Wylde barrel.  I also shot a few 22 rimfire through a Department M-16 with a chrome lined 1:12 twist barrel.

The only way I think you could ever hurt a centerfire 5.56/223 barrel with a rimfire conversion is if you had an out of battery ignition and lodged a bullet in the barrel and fired another round.  I had a couple of OOB ignitions after I peened the end of my DPMS barrel.  I always checked the bore and never had a problem.   With the low temperature and softer lead barrels of rimfire ammo I don’t think you could wear out a chrome moly or chrome lined 5.56/223 barrel using a 22 conversion.

Even if you did plug a gas port or filled a gas tube with lead which caused malfunctions with a centerfire it is a simple fix to remove a gas block and gas tube.  The lead could be easily removed with a torch or soldering iron.  With the savings in ammo a person could afford to buy a new gas tube instead of melting the lead out of the tube.

@VASCAR2

I have an adjustable gas block & I was wondering if the lead build-up on the threads if threaded in all the way to close off gasses would cause the threads on the stud to get stripped when I backed it out.

I wonder if coating the internals with welding spatter guard would help.

I never used an adjustable gas block with a 22 conversion.   If it were me I would close the gas block completely since the 22 conversion is blow back.  If the screw for the gas block got sticky I’d use Kroil which would probably free the screw.

On gas piston uppers you can run a 22 conversion if you remove the operating rod.