Been itching for a 22lr AR.  Snagged a mew old stock banshee 300 4.5 inches off of GB. Hasn’t been much fun from the get go.  Shipping and pickup took forever, and I rolled the dice on it and bought some stuff before I had the gun in hand.  A timney mpx trigger, a sig stock, and a bunch of cmmg mags.

I sent my paperwork to SBR it in before I even shot it, and had I not done that,  I may have let it go.  The timney trigger proved to be too light and didn’t work well at all, the stock trigger works ok, but the magazines are horrendous.  No feed, double feed, you name it, many of them are junk.  Some are good,and I’ve been marking those with a paint pen… some are pure garbage.  Are there better mags for these things?

The sig stock should be awesome, can’t wait to try it once my paperwork gets back. I’ll put the trigger back on EE to cut some losses.

Today I had some failure to eject cases.  Kinda weird. Need to call cmmg and see what they have for info.  

To my discredit, I was using bulk federal hollow point….so that probably doesn’t help.  Grabbed 1000 rounds of cci mini mag, so hope that helps things.  

Any insight to getting this set up would be appreciated.

15-22 mags work way better. Get the a better mag adapter to make them work. Between those mags and BoreBuddy upgrades (extractor and pressure plug at minimum) you will have it running sewing machine smooth pretty quickly.

I will buy mags and adapter for sure.

Tell me about the pressure plug. I have a picatinny rail mount on the back for now.  Can I stuff some o-rings to fill the gap between the upper and lower? I’ve done that and it feels pretty tight.  But I’ll buy whatever I need.

Oh, and I’ll follow the polishing in this thread
https://www.ar15.com/forums/AR-15/How-to-make-your-AR-22-run-smoother-NOW-with-pictures/15-526872/

I just built a dedicated .22 AR. The CMMG mags would not run....stovepipe/FTF/Dbl feed. Rimfirecentral membes recommended these mags....they run perfect:

https://www.joeboboutfitters.com/Blackdog-AR-15-22-Sonic-Weld-X-Form-Magazines-w-p/bdm-sw-ss.htm

Thanks.  I’ll look into getting one to test.  I think the cmmg mags are a big part of my issues.

I shoot a 9" CMMG dedicated upper in my SBR for Steel Challenge.. I've upgraded the firing pin to a Bore Buddy pin and added one of their wire EDM extractors...the trigger is a stock LaRue MBT with stock springs,, topped with a Holosun 510c green reticle...I run it wet and use a worn 5.56 chamber brush on a T handle to clean the chamber as Steel Challenge requires a lot of reliability... along with the bolt face and the shoulders of the collar unit... I shoot about 1200 rounds a month, and to the best of my recollection other than a broken firing pin (before Bore Buddy) have had no failures to function

15-22 magazines with extended use will wear a groove in the feed lips where the cartridge rim rides... watch for this...I use Black Dog stainless feed lip sonic welded mags and load to 23 rounds... they give me excellent service with both CCI Standard Velocicy and Blazer... bulk Federal had serious priming compounding problems a year or so ago so I stay with CCI, and IMHO the wax lube on the Blazer feeds better than MiniMag copper wash


If you mix and match parts, be advised that older CMMG collars and barrel stubs are shorter than current production... a short older collar on a longer stub will shoulder on the feed ramp and not contact the barrel itself, and can shear the feed ramp off.... regards Les

I’ve never had satisfactory performance from the CMMG mags.  I prefer the S&W mags with the redo-mag adapter or Catch22 clip-on spacer.  Both of these are intended to provide last round bolt hold-open but I can see that’s not your concern right now but the added benefit is near flawless feeding.

The Black dog mags are my 2nd choice. Always had good luck with those; especially the steel feed lip variety

I also have a few KRISS mags that work pretty well.

The polishing will certainly help as will a few of the Bore-buddy upgrades mentioned above.  The high velocity ammo should help too with the 4.5” barrel.

Be careful though….these things are fun. Next thing you know you’ll have a safe full of them.

Does their dedicated gun have the standard bolt group the conversions do? On my folding lower, I put a little 2mm silicone bumper on the KNS rail adapter to take up the little bit of forward/backward slop and a lot of my reliability issues disappeared.  It was a random Hail Mary since there was 2-3mm of movement when the bolt cycled, but I’m not complaining about a 2 cent fix.

I also read that polishing thread years ago and did it all.  I expected all kinds of problems that just never happened.  I've skipped the polishing in subsequent builds, and they work fine too.



It seems that the ultra short barrels often don't generate enough velocity in the bolt.  The CMMG bolt is light, but pistol length barrels and the lower velocities they make might only provide marginal function for something made to function on 16 or 20 inch barrels.  I have ammunition that will not cycle in a Ruger MKII 5.5 inch pistol, but is reliable in a 10.5 inch barrel.



I think your ammunition choice is fine.  It's HV and should push about as hard as any other HV.

To me CMMG magazines and Black Dog magazines look like the same thing, but I hear complaints about CMMG mags, and nothing but praise for Black Dog.



I've made buffers from toilet washers from Home Depot.  I've also used those adhesive silicone dots for kitchen drawers.  Wool adhesive discs for chair legs are easy to shave down to a correct depth.

Be careful not to make it too tight.  I mixed and match items once so the CMMG BCG rails may have bowed slightly with the whole thing closed.  I've also had one with so much room that the collar came backward with each cycle of the bolt, and that one is extremely reliable.  Taking the parts to the range and experimenting may get you farther on this than what others did with theirs.

I'm a fan of S&W 15-22 magazines and a bolt latch that works.  The 10 round short magazines are easy to load and don't get in the way.  LASnyder is right about them being wear items.  Clipping some coils out of the magazine spring seems to prolong lip life without any reduction in function.





The frame and bolt are the same, but instead of a chamber adapter, dedicated kits use a collar that locks onto a barrel stub with a detent ball.  If you have the conversion and want to make a dedicated upper, Bore Buddy makes the most affordable dedicated collar and it has some adjustability the CMMG or RTB versions don't have.  https://borebuddy.com/product/22lr-barrel-collar/

I have a 4.5" AR22 that I put together myself using a CMMG bolt and dedicated barrel. I only use Black Dog Machine magazines and have not had any issues. I am not running a buffer plug so there is no buffer tube nor a place for a pressure plug. I did have issues with standard velocity ammo after I installed a Bore Buddy bolt weight. But that is a known issue with the 4.5" barrels. The pistol functions flawlessly with the bolt weight and high velocity ammo.

Thanks for all the replies!

Ordered some new mags, will polish up some bits, and give it another shot this week.  Hell, fingers crossed I can even rum my flat MPX trigger in it.  That would make my day! I need to order some extra pins and extractors and hopefully that gets me going. Just shocked how poorly it ran out of the box- some of the Cmmg mags feel like they have featherweight springs in them.  Lol

These rimfires are new to me, and I hope to be able to figure them out.  Have a DA mask (hopefully) coming out of jail soon, so high hopes I can get the Cmmg dialed in. I bought the DA for my tx22, but that’s another thread!  Lol.

That's what I figured, but wanted to confirm that their full firearms are the same as a dedicated kit.  I've got a build with dedicated barrel, collar, etc.  Just wanted to make sure before giving further advice.

That was my reaction ...at first.  Then I tried to load it.  The spring in mine may barely be there at first, but getting the last few rounds takes a lot of force and swearing.  I've never taken it anywhere to shoot.

Also this^

Very informative post!

Bit of an update

I polished some bits, got some CCI mini mags, and waited for my black dog mags to arrive.  Feeling lucky, I reinstalled my Timney MPX trigger, and set off to blast.  A WORLD of difference. I suspect mag feeding, or lack there of, was the main problem.  The mpx trigger ran flawlessly

Only hickup I have been getting is the occasional spent casing stuck and not ejecting.  I’m hoping a bore buddy charging handle inset will fix that, and also may throw in one of his extractors with a stiffer spring.  The stuck spent casings seem to be more problematic as the gun dries out.  Problem exists whether shooting fast or slow.

If I can get the stuck case issue fixed I’ll really be happy!  Oh, and fingers crossed on a quick SBR stamp turnaround!

In my experience 22 LR firearms run better the more they’re shot.   It is kind of amazing how filthy a 22 LR AR-15 gets after three to five hundred rounds.   If your getting failures to extract CMMG recommends buzzing the chamber of their barrels.   Basically put oil on a bronze brush attached to a short cleaning rod spun by a hand drill.   I usually polish the chamber with Flitz on a barrel mop with a hand drill.   Either method helps eliminate stoppages.  

I have a few AR-15 22’s and I had my five year old Grandson shooting with a bipod off the bench.   He was getting failures to extract and the brass was getting caught in the charging handle channel.   I’ve never experienced that failure with a CMMG AR-15 upper but he just wasn’t holding the rifle rigid enough.   I got tired of clearing malfunctions and on the third AR-22  which is the oldest most shot CMMG he never had another malfunction.   All the other AR-15’s my Grandson shot had many thousands of rounds through them without a malfunction but one was pretty dirty.   Even lubing the dirty CMMG didn’t keep it from getting stove pipes.

I even got malfunctions with the polymer CMMG rimfire charging handle with my Grandson shooting.  The reason I mention this is if there is unnecessary movement of the rimfire bolt carrier in the receiver it zaps recoil energy.   With no buffer tube and buffer/spring there could be enough space to allow the rimfire bolt assembly to move under recoil and zap recoil momentum.   On a new build with no stock I could see where it would be easy to duplicate the same situation as with my Grandson shooting.   You never really think about limp wristing affecting semi auto rifles but it can happen.

My CMMG dedicated AR-15 22 LR uppers are typically as reliable as any 22 rimfire can be.   The only parts I ever remember changing has been a broken firing pin and spring.   Since I started using two stage match triggers I get a lot better firing pin life compared to when I used single stage mil spec type triggers.

Glad your getting your 22 AR running better nch209.   I have seen several 22 LR barrels take a lot of shooting before they seasoned and get better accuracy.   My most recent 22 LR upper is still getting fliers but the more I shoot it the better the accuracy.   When I first started shooting my last upper it was shooting patterns and not groups.   Now this particular barrel is getting pretty decent groups with one or two fliers out of a ten shot group.   As this barrel has been shot the fliers are fewer and tend to stay closer to the other rounds in the string.   For shooting steel plates this is a non issue.   I have other 22’s that are tack drivers.

There has been a few complaints about the new CMMG magazines having weak springs. Some guys on Rimfire Central swap the CMMG mag springs out for S&W 15-22 mag springs which seems to help. But it is still hard to beat BDM or 15-22 magazines for reliability.

As far as getting empty cases stuck between the bolt and charging handle, you can buy an insert or fill the charging handle with epoxy or RTV. I have a Bore Buddy CH insert in one build and filled the CH with RTV in another. Both methods work. I am also running Bore Buddy firing pins and bolt weights in my CMMG bolts and haven't had any issues or broken firing pins yet.

I have to say that my 4.5" pistol build is fun to shoot and pretty darn accurate. I do shoot it with a sling pushing the pistol out away from me. This method makes for a pretty stable shooting method. I was originally taught this shooting MP5 pistols.

Been slowly getting bore buddy parts to help increase reliability. My DA mask should be here this week, and want to run it and see how it does.  Still get one case jammed between bold and chamber per mag which is perplexing. Perhaps a bb weighted bolt to slow things down.  Yes, it has the CH insert and the cases are getting stuck on the bolt face side ways. Got my stamp back so to getting closer.  Need to get the stick cases dialed out and the. It should be a favorite!
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Your pictures are excellent.

I get exactly that malfunction with some kinds of ammunition.  Specifically I've a batch of CCI SV with lots of duds and this kind of jam.  It doesn't happen ever with RWS Rifle Match which has very consistent speeds and ample recoil compared to most subsonics.  I always use a bolt weight, which I shouldn't do for some slow loads.

This makes me think it's a velocity issue.

Do you get this with HV as well?

So far I’ve only run CCi mini mags through it.  No bulk ammo.  I’m gonna burn through the rest of it, and then buy a variety of other stuff to see if I can get it cleared up with an ammo change.  Foolishly I bought a bit of Cci mm thinking it would run well.  (Again, not SURE it’s an ammo problem, but need to test some other flavors)

I know this doesn't help you but I have a MK4 and love it. No issues that weren't obviously ammo related in 1500 rounds so far.  I'm using the mags purchasable off of CMMGs website. I hope maybe that info is of some use. Otherwise, my condolences.

AR22's with a 4.5" barrel will not run any standard velocity ammo if one is also using a Bore Buddy bolt weight unsuppressed. It might work with a suppressor but I don't have one to try. I have stuck with running CCI Mini Mag, CCI AR Tactical, and Aquila Super Extra 38Gr HP and 40Gr RN without issues.

Is it specifically the folder that’s giving you trouble? I put a little 2-3mm silicone bumper on the buffer tube ‘insert’ when I was having issues and it solved it in a hurry. (Mine is a folder) There is enough wiggle room for the bolt to be robbed of some energy when the whole assembly can move a touch, which was causing feed and eject issues for me.

Short term, I’d just do a dab of RTV on the rear of the .22 conversion, let it set, then install. Should be a lot more snug, but easy to remove if it doesn’t work.

It wouldn't surprise me if the folder is allowing the entire bolt to move enough to cause issues. And some RTV is a good temporary fix to know for sure.

I have a screw in plug that sticks out enough to keep the bolt from moving on my 4.5" build. I use a buffer, spring, and pressure plug on all my rifle builds.

^

Thanks for the above info.  Next chance I’ll get, I’ll show my folder setup to hopefullly get some advice on whether folks think it’s mitigating movement of the bolt.  Heck, all short cmmg guns are coming this way now, so there should be a fix….

(Spoiler, I’m running a few Orings ahead of the pic rail on the buffer tube and am thinking everything is fairly tight…but I’m new to all of this so opinions would be appreciated)

More to come…

I shoot bulk Federal hollow point in my CMMG conversion and it runs fine. IIRC that is what CMMG recommended. Unlike my other .22s I clean and lube the conversion unit after every range session.
The Smith & Wesson 15-22 mags work great in mine as do the CMMG brand ones that came with the unit. Mine is in a clapped out m16 upper I got for scrap metal prices from a great arfcom EE deal.
I’m not saying it’s never jammed but it’s run good enough for plinking and inexpensive range sessions shooting scrap metal in my back yard.

A quick finding…

I did a look over and function check just now… and an odd thing has surfaced.  This has a cmmg ambi charging handle, and if used to pull the bolt back via the right side and RIDING it home, it’s smooth as silk, but riding it home via the left side the bolt binds up 1/4 of an inch before seating.  Something is catching and stopping it, but a push on the charging handle easily sends it home.  I wonder if I have a burr somewhere giving me grief.  Again, new to this rimfire ARs.  [recall this is a new old stock cmmg 4.5 complete setup]. I hope to be able to find time to shoot and tear into it more this week.

I built a slap together M4 22LR with CMMG dedicated M4 style 22 barrel, A RTB dedicated collar, and Spike Tactical AR15 conversion kit ( No longer made).  Adding a Buffer Tube plug and charging handle liner ( 3D printed PLA+) and an Buffer that I modded the print file for double thickness (3D Printed w/ TPU 95a). I Run both Maddog and CMMG mags with no more problems that any other semiauto 22LR I have. Mine also likes to be run "Wet" or heavily oiled. Adding the Buffer plug and Buffer smoothed out the bouncing of the action.

I don’t run ambidextrous charging handles but I wonder if the conversion bolt is squarely aligned with charging handle.   If the 22 LR bolt guide rails are not welded squarely with the end plate this could contribute to the drag on the charging handle.   If the collar is not sitting squarely on the barrel stub this could cause problems.  The guide rail for the bolt has a notch to hold the bolt properly and needs to be square to the barrel.

I’d look for unusual wear on the charging handle and the top of the bolt.   My charging handles show wear marks evenly where it rides inside the upper receiver.  You can also see wear marks from the bolt cycling under the charging handle.


To much play in the conversion bolt assembly in the upper receiver might permit the charging handle to bind on one side.   Not having enough forward pressure might be letting the bolt assembly move to much in the receiver and inhibiting the free movement with the ambidextrous charging handle.

Thanks for the continued replies!

Some updates.  I repolished the inner bits, cleaned and oiled pretty heavy, and removed that plastic bit on the bolt with the groves for the forward assist.  CH looks ok, but above post makes a lot of sense on what to look for.  I ran mine more wet… and everything seems to be working better.

That said, this was a new old stock complete from CMMG so maybe a break in period helped.  In short, yesterday I had 1 malfunction in 100 bangs- today zero in 50.  The malfunction was one stovepipe. I’m at day 222 for my Mask, and hopeful that it runs fine with it, because I’m just starting to get happy with it.  

Aside from polishing it, this is my build so far…
BD mags
Timney mpx trigger (awesome)
Sig mini stock (yes, it’s a SBR)
Scalarworks 1.42 mount
Holosun 507
BB extractor
BB heavier extractor spring
BB buffer
Custom oring makeshift buffer tube filler
Radian ambi saftey
DD grip. (Think I’m the only one who likes these.  Lol)

If it runs 99% with the mask I will be happy! Fingers crossed.

Don't know what Black Dog magazines you are using, but I've tried just about every AR22 magazine and these are the best of the breed.
Combine the metal lips with loading button similar to that on the S&W MP 15 22 magazines for easy loading.
Run flawlessly on full auto on my Colt M16 with a CMMG dedicated .22lr upper w/anti bounce weights and all the recommended mods mentioned in the "How to make your AR 22 run smoother" thread under the "Important Rimfire Threads!" sticky at the top of this page
Had to remove some material (very minimal amount) with a hand file from front and back to insert into another rifle that has an Anderson lower.


https://www.blackdogmachinellc.net/3rd-generation---metal-feed-lip-magazine-for-ar15-22-conversions.aspx


RCA

On my RTB upper i had a bit of front-back play so before my first range trip I brought a hose washer with me to the range.
Had occasional FTF so I droped in the hose washer as a makeshift pressure plug, issue resolved. Ordered up a pressure plug the next day.

I think the Bore Buddy pressure plug is $7 and they also make a better firing pin. These are cheap upgrades for reliability and I'm not the only one who recommends them.

Only ordered from BoreBuddy once and had no issues. He makes a lot of unique products that are well reviewed,

This is what I came to type. My 2 have been great.

Hope you got everything sorted out.. But I cringe every time I see people say they are running their dedicated .22 or any other .22 good and wet.. Just my opinion and what works for me is never run a wet lube in a .22 at all..Use dry lube.. Keep your slobbering of wet lube for your Centerfires.. Using wet lube is just asking for a instant sludge, slurry, gritty jam causing mess in a .22 rimfire in just a few shots depending on crappy the ammo is you are running.... A tiny drop of wet lube may be OK on the extractor.. But never slobbering wet as some say they do..Take it for what it is worth..But I have not put wet lube in any of my .22s since way back when I was a kid.. Never knew any better then.. I cannot tell you how many .22 semi autos I have bought over the years and such really cheap because they could not get them to function..The reason why was the wet lube.. Then it gets worse.. They think that dumping in even more wet lube is the answer,LOL  I clean em, dry lube them, and they run perfectly.. It is amazing the amount of gunky buildup the oil can attract in a very short time.. It is just a magnet for every dingy particle the rimfire produces when fired.. And the oil never allows any of it to leave the action at all.

Could this just be the CH hook resting on the upper receiver?



On the nose.  You can get an idea of how much grit 22lr generates by shooting hundreds of rounds on a hot day.  Your sweaty support forearm will be covered in it.  Want most of it to stay in your action?  Use lots of oil.

I clean with Hoppes no.9 and just wipe it off.  600 rounds later fine carbon or soot will show up on the frame rails, firing pin and its channel, but none of the coarse grit will stick.


I generously oil centerfire AR bolts not for function as much as for easy clean up.  It's a different animal.