Freshly back from CMMG "Service ", for the  second time.
4 magazines loaded, one hundred rounds.   50 each: CCI minimags,  and Federal 40gr rn.
total of 24  cartridges,  fed and succesfully fired.
76 rounds  failed to feed, and are now bent, mangled ,unusable 22LR cartridges, on the ground.
This CMMG complete  22LR upper is the singulary most unreliable mechanical device I have ever owned, literally the shittiest manufactured article I have ever attempted to operate.

I once paid $120 for  a 1973 Ford Pinto that was more reliable.

I don't know what to say.  Been lucky with all my drop-ins and dedicated uppers.  The one that caused me the most problems is a CZ V22 but feeding is not the main problem.

I have ignition issues with my CMMG LH but feeding and ejection have been 100% from the first shot.  My Kuehl and Spikes(assembled from parts) uppers both needed break-in but only a few jams during the first 100 rounds.

What mags are you using? If earlier CMMG (gray ones?) the tabs on the back often make the mags a tight fit in the magwell and can cause feeding problems. Later CMMG hi-caps have some issues as well.

YMMV

FTF seems like it definately could be a mag issue.  What kind of mags you using?

25 round CMMG magazines, light graY color.
Quantity 4, all fit loosely in magazine well, and ALL fail to feed most of the time.

Have you tried Black Dog Machine mags?  Palmetto State Armory has the steel feed lip models on sale at the moment.  Sorry to hear your upper is having so many issues.

If you are so disgusted you want to sell it make me an offer.

Please set your camera to "macro" and post a photo of a close up of the breach face side of the barrel.

ETA:   What hammer are you running?



Cheers, Nagorzo

I'll buy the complete upper (barrel, receiver, bolt, carrier, etc) sight unseen for $175 shipped.  I'll give you another $25 for the magazines.

Off hand - the only other thing I would check is if the bolt is dragging on the bolt catch.  Some bolt catches can cause problems with cycling with Ciener type .22 bolts.  I think there was one particular brand but I forget which one.

In my experience both my Spikes and CMMG both had failure to feed issues with CCI Mini Mags.  I believe it was the film that is on that round.

Following one of the threads on here I cleaned the hell out of my chamber and buffed the feed ramp on my custom upper that uses a CMMG kit. Now the only issues I have are ammo issues. The thing runs like it should now. Seriously if you haven't done that yet. You need to. My feed ramp looked horrible when I actually looked at it.

http://www.ar15.com/forums/t_3_15/526872_How_to_make_your_AR_22_run_smoother_NOW_with_pictures.html

I will inspectb the chamber.
The upper has been back to CMMG factory TWICE now, I'd expect they would have checked or corrected any chamber issue.
Is this  ( CMMG ) design extremely ammo sensitive?
My  10-22  will feed hundreds of thousands of rounds without fail...  I get maybe  1 or 2 bad primers per brick of cheap stuff, but they ALWAYS feed from the magazine.

In com,parison, the CMMG will succesfully feed around 25%, leaving  dozens of bent, mangled unusable 22's on the ground for each box of 50 attempted. Many ammo brands and style s   have been similarly dismal.

 Great for malfunction drills , but terribly frustrating  for  target practice.

I have almost 5000 rounds through my CMMG dedicated upper since the last feeding issue or jam.   And that's running an old Ciener parkerized bolt without any of the various improvements of the CMMG version.    The only failures have been bad primers and 2 squibs I noticed and had to clear before shooting again.

Its actually not that finicky.

The only time I've seen that rate of jamming on an 22LR –– and especially the mangling of rounds so they will no longer chamber in any weapon is where there have been firing pin strikes that have buggered the breach face and chamber area.

I would be interested in which hammer and hammer spring you're using.  There are reports of lotso jamming with notched hammers.  Also some reports that an out of spec bolt catch can drag.  

Of all 22 rimfire I've used I have the best functioning with Federal 36 grain HP bulk 550 from Walmart or the blue 525 round bulk.  I noticed when testing BDM mags for the CZ  V-22 that CCI Mimi mags had softer brass than some other 22 rimfire ammo.  The CCI MM  seemed to let the case wrinkle and bend the bullets more than other ammo.  

Every 22 rimfire design I own seems to have preferences for ammo.  Find what  ammo your 22 rimfire likes and stock up.  My CMMG dedicated uppers, conversions and DPMS 1st gen uppers functioned great with Federal bulk.  My Advantage Arms Glock & 1911 kits  seem to work best with 36 grain Remington bulk HP but other guns choke on Remington.

Do these grey mags have the CMMG GEN 1 BHO followers (black 2 piece followers)?   I had some issues with my CMMG upper when using the GEN 1 BHO (grey) mags; But, since I switch to the S&W mags (and later to the CMMG GEN2 black BHO mags) I've had no issues.   None at all in many thousands of rounds.   Both Federal bulk pack and CCI Mini Mags run perfect.  

If you do have the gen 1 BHO followers, try switching to a standard Balck Dog type follower (no BHO ) and see if that works.

If you don't have the GEN 1 BHO followers, I'd still try a different type of Mag, just as a diagnostic point.   A friend (or stranger?) at the range with a std Blackdog mag.

Also do you use the CMMGs BHOA (the Bolt Hold Open Adapter)?    Again, just as a diag point, try it without the BHOA.

I have been shooting with .22 adapters for some years now.(Four or five different manufactures or models)  Been through tens of thousands of rounds in several different rifles. Between that, and what has been posted here I and others have learned a few things.

1) There are many variations in .22 ammo

2) There are many variations in our so called "mil-spec" lowers

3) There are some hammers that just don't work with some .22 bolts  (true for all the .22 conversions and dedicated uppers I have used)

4) CMMG conversions and uppers have for the most part been the most reliable on the market

5) If a unit goes back to the maker they do actually test them and make sure they work

Besides Spikes, Cliener, and CMMG parts I also have a Tactical Sotutions upper. I had trouble with it working with some lowers. Tac Sol wants you to ship back EVERYTHING, upper and lower so they can find the root cause. While this is a bit of trouble the fact is they were correct about doing that as they could isolate the real problem.and insure that your upper would work with your lower. They even re-designed their bolt so it would work with the RRA two-stage trigger assemblies.

A few years back Spikes was the "hot setup" with their plated kits. Problem was they gave many of us fits as they refused to work properly for some people. Again it was finally figured out that some hammers just didn't like the Spikes.

So, before trashing a company over its allegedly poorly made product some find it more advantageous to just take the time to get to the root of the problem. There are tens of thousands of CMMG conversions and dedicated uppers out there that run flawlessly day in and day out.

Try the conversion on some different lowers. You might be surprised. If the problem continues with a selection of lowers then blame the unit. If the problem stays with just one lower then figure out what is wrong with that lower. Sometimes the smallest things can make a big difference, I know...a few of us here have spent hundreds of hours working with this stuff. (SpecOps13, Shadow Cop, and others) and have learned a thing or two. We may not have all the answers, but we keep plugging away at it.

+1 - I've shot Cieners, Spikes, CMMG, Colts, DPMS, 261s, Air Force and even a CZ V22 (got kinda out of control buying issues on .22 conversions).  Dedicated uppers = Kuehl, Spikes, CMMG, KKF and the CZ.  Only unit I haven't run is an original Atchisson (pre-Ciener) as it does not fit the uppers I've tried.

The one thing that threw me for a loop was variation in mag catch dimensions and mag catch location on lowers.  I've had perfectly functioning units go south with a change in mag catch.  Took some extra mag tweeking to get it to run well again. And don't get me started about differences in magwells  

One other point I'd forgotten.  The Ciener type units I have don't seem to like tight mags - a little looseness in the mag well appears to result in better reliability.  
During our annual shooting sports fair almost all jams in my .22 ARs could be traced to novice shooters holding the mag or to the 30 round length mags touching the top of the shooting bench.  The latter happened often enough that I pulled all the longer mags and only use the short 10 round mags (BDM, Ciener & CMMG) at these public events..

YMMV

I've been more than happy with my dedicated CMMG .22 upper.  Its never had a hiccup despite variations in ammo brand, velocity, suppressed and unsuppressed.  I'm surprised how reliable its been cause its gotten pretty nasty after shooting suppressed for a while and it keeps working.  So I'd keep working at it cause they've been wonderful for me.  Also had great luck with them for my .223 upper.  I am a CMMG fan boy.

Yea, when you find something that is reasonably prices and just works super well its easy to be a fan!  Meanwhile, I hope the poster finds out what is really wrong with his rifle or conversion. I have worked with the good folks at CMMG and know they would not send a unit back without testing. They are sensitive to their customers experiences and like things to work right. They don't have control over what lower we use however.

Negative... NoT notched hammer.
DPMS lower, with DPMS parts kit.
ARMALITE Lower, with Armalite parts.
COLT's 6920, as  built in Hartford CT
Arfcom lower with RRA lower parts.
Superior Arms lower with DPMS parts.
........... All five of the above function at 100% as assembled with their respective centerfire 5.56mm uppers.
 only 800 rounds through the Colt, but all the others have from 2000 to 5000 through them, and none of the 5 rifles has had a single malfunction of any kind with any brand or type of centerfire ammunition.
.. All five  lower assemblies  have served as host to the CMMG dedicated complete .22LR upper, and so far, we have ZERO function with Remingon ammo.
...... ZERO meaning two entire 25 round magazines of attempted to feed from magazine, and now mangled, disfigured rounds, on the ground ... 50 wasted  cartridges, destroyed with OUT a shot fired.
4 or 5  fed and fired out of a full box of Peters .22 Hi-Velocity.
CCI miniMags went 20 percent feed and fired today, on the Arfcom lower.

AMAZING STORY:, I actually fired 20  Federal champion 40 gr hi-velocity consecutive, without  malfunction.
Yet to duplicate this feat of great fortune...

The diagnostic next steps are as follows:

1.  Check for evidence of dragging of bolt on the bolt stop.
2.   Test with different magazines.

These two are the most likely given CMMG's having had the device and it seeming fine on their end.

3.   Measure firing pin protrusion.   Remove and clean firing pin, make sure its not separated –– which would result in jams trying to feed a round with pin forward.
4.   Carefully inspect breach end for burrs, firing pin impact marks, etc.  Outside and in a save location, safety on, slowly cycle a mag full of ammo –– see if you can tell where the hangup is happening.
5.  Check frontward/rearward movement of entire with gun assembled.  Consider replacing buffer and spring with carefully measured wood dowel or one of the conversion pressure devices.  (Movement of this sort absorbs a bunch of the recoil impulse needed to cycle the conversion –– this seems unlikely given your symptoms).

These last three all seem unlikely given that CMMG has examined it, but I would check them anyway.

Still wondering, if it works with other mags, and without the BHOA.

The CMMG's and others were designed with 36 gr. bulk pack.
Use Walmart Winchester or Federal 36 gr. hollow points for break in.
Never use Remington. It's actually not recommended to use.

Some of the Evo mags will not feed 40 gr. They were supposed to be labeled.

Again, I recommend the TACCOM reliability kit.
Longer, better designed firing pin will give better strikes.
The pressure plug will keep the bcg from moving. Movement absorbs firing pin energy and can cause feed problems.
Enhanced Extractor gives more positive Extraction.

Dave N

Winchester or Federal Bulk doesn't lead up the barrel much?

Dont see why they would lead up the barrel any more than anything else.  They are all lead projectiles.

They burn cleaner and the copper wash serves as a better lube in the way as it doesn't leave as much residue.
I can only tell you my experience. I've not had one barrel lead up including my CMMG M4 LE with over 23K through it.
For groups, I will shoot Wolf MT or Eley. For plinking I use Fed or Winchester copper wash bulk.
Some of the 40 gr. bullets were too long to feed from the Evo mags. It is said to be corrected in the later mags. I don't know as I do not have any of the later mags.
Dave N

In all deference to the OP if I had his problems and had sent the upper in to CMMG twice and still have issues I'd be pissed too.

OP:  Surely CMMG test fired the upper before shipping it back.   So it must have worked for them.   About the only thing that would be different would be the mags and the BHOA device if you're using it.   Did you ship the mags back with the upper to CMMG?  I know this has to be frustrating.

That's why I've already asked twice about the mags and BHOA, but so far, no response. ????  

Yes, the SECOND  return of the dedicated CMMG .22LR upper included all FOUR factory gray color 25 round CMMG magazines.
 None of the four  CMMG magazines will reliably feed ANY ammunition of any brand with any one of 5 different lower receivers.
This is quite literally the most unreliable mechanical device I have ever owned.
.
.
.
No Bolt Hold Open Device is installed.
.
Purchased a  Smith & Wesson M&P15-22 today.
feeds EVERYTHING, without fail.
To Repeat, Brand NEW from the factory box, M&P 15-22 FEEDS and FIRES all .22LR cartridges, every time, without fail.

I'm glad you got something that runs for you.

My offer from the prior page stands:  "I'll buy the complete upper (barrel, receiver, bolt, carrier, etc) sight unseen for $175 shipped."  You can keep the mags, I've got plenty.   Maybe I'll get it running...  maybe not.   But I have a curiosity aroused in me as to what the hell is wrong with that thing and I'd love to scratch the itch.

Cheers,  Nagorzo15-1

Yes. Returned CMMG upper, with FOUR CMMG magazines to CMMG factory, they had it for several weeks,
 claimed to have it running 100%.

I had a lot of problems with mine, it would only run the winchester 333 packs and got lots of ftfs. With the federal 550 bulks packs it would not run more than a few rounds till failure. When I looked at the failures they either hung up or the bolt did not close all the way.
The chamber seemed to tight for me and the bolt spring too light. I made the following mods to mine.

1. Add a small spacer im my bolt to make the spring slightly stronger when near closing.
2. Polished out the chamber highly with a rod, 440 sandpaper and a drill.

Before the federal rounds when in very tight, even my hand. Now they go in like they should. Last outing I went 250 rounds with out a FTF. Before I would go about 50 rounds and give up for the day.

Did you fit the mags?