If you are like me, you want your firearm to be 100%. Sure, we can get a dud round with .22, but I want the gun to feed and eject like it should. My rifle seemed to be running pretty good but then every mag one or two rounds would fail to feel properly. These would jam at an angle as they lifted up off the magazine and tried to swing into the chamber. You know the routine, drop the mag, clear the round, re-insert the mag, chamber the next round, start shooting again. Lets be honest here, we shoot .22 ARs to BURN ammo, not do the single shot rifle thing. That is for bolt guns!

Two common complaints with all firearms and especially .22 AR's are failure to feed ( Here called FTF) and failure to extract (Here called FTE) We could break these down further into sub-categories but lets keep this quick and easy today. Also, both of these conditions do have some overlapping causes too, so I will just go over the steps to deal with both. I won't get into magazines here. Let's face it, with the mags we are currently using on .22 AR's we aren't going to be dealing with making adjustments to feed lips, etc.

On your new dedicated upper you want smooth parts. I am talking smooth like shiny and slick.  We want that round to have an easy, unobstructed pathway up from the magazine (at a slanted angle),  up against the feed ramp and then up and around into the chamber. Next, its going to fire, the brass will expand and then contract, and then its going to be pulled out and pitched aside. Our firearm was designed to do this and do it very quickly. Its like a beautiful dancer doing all these moves in perfect time.  If we add any excessive friction to this we are going to have problems. Stop and think about this process in slow motion, one step at a time and picture this round rubbing against all these un-lubricated parts

Here are some simple, DIY steps you can do that will make any firearm run better.

Lets do the chamber first. This area has a lot of metal moving across it and oiling it is out of the question. So, make it slick. Slick here does NOT mean it has to look like chrome. What we are looking for is a smoother surface. All machined areas will have marks where the metal was cut. Small marks are NOT a problem as long as the area is smooth. We don't want to remove metal here as it could make the chamber too large. But, we do want it clean and smooth. On their site CMMG will tell you to take a chamber brush and chuck it in a cordless drill. Then, spin that brush in that chamber until the brush gets warm. I do with with a little Hoppe's #9 to clean things up after a big day at the range. As I spin the brush I am moving it in and out and letting it smooth out the area. I don't want any ridges or rough spots that can grip on the casing or the nose of the bullet. I once had a  .22 Brand "X" conversion that had a plated finish that got into the chamber. I actually had to take some 400 and 600 grit emery cloth (sand paper) with a touch of thin oil on it and lightly spin that in the chamber until it was smooth. It worked great and saved a good unit from being sold due to its unreliable operation. This is NOT something you would normally do as you can enlarge the chamber and cause other problems. This was an extreme case.

Tools for cleaning the chamber: Note a brass bore bush mounted to a cordless drill motor. I dip this in Hoppe's 9 to clean the chamber. A little light oil if you are smoothing it up. CMMG says run the brush until its warm on their forum. As you are "buzzing" the chamber I like to move that brush in and out as it spins. Many recommend you do this after every other, or every, range session. It really depends on how much you shoot and the ammo. There are days when my rifle shoots many hundreds of rounds. I definitely want to buzz her out after that.



Brush in chamber. Remember, its only the chamber area that needs the polishing job. Some machining marks are normal from the reamer that cut the chamber. We just want to smooth off the rough edges. We don't need to go in so far as to hit the rifling. That will be taken care of during normal cleaning.



Once the chamber is nice and smooth lets work on the next common feeding area, the feed ramp. That is the sloped part where the round coming out of the magazine first contacts and gets pushed up into the chamber. Any roughness here will results in FTF, jamming, etc. Its amazing how little roughness here can really screw up the dance.  Here we will use a Dremel type tool. Do NOT use a grinding wheel or sanding wheel! The angle on the feed ram is critical and any changes to it can give some nasty bad results. What we are trying to do is make is slick and smooth.  We are going to use one of those little white soft polishing wheels on this. To do this you need some polishing compound that is made to polish steel. This will be listed on the compound. Pay attention to this as there are four to six different compounds you can buy, each for a different material. You can get these many places. Sears, Tractor Supply, etc.

Polishing supplies:




Put on your safety glasses !  (OK lawyers, there you are!)  Chuck up your white cloth polishing wheel. Spin 'er up and apply some compound to the wheel until the wheel is the same color as the compound. Now, using a light back-and-forth motion proceed to polish the feed ramp. After a bit of work is will begin to look like its chrome plated. GOOD! This is what we are looking for. Keep polishing until that thing looks like a chrome piece off a show car. It may have a few smooth ridges or lumps on it from the manufacturing process. Don't worry, its the surface we are concerned with. As long as you can put a shine on it you should be OK. We do NOT want to try to use a grinder to take those out. Doing so may well change the angle on the ramp. This will cause a new set of problems that will be difficult if not impossible for you to fix.

So, make is smooth and shiny and it will run better. I have had to do this on many firearms over the years. It has saved me many headaches and solved many feeding and extracting problems. There is a lot more to know in these areas but for simple .22 these two things will solve a majority of our issues. You could send it back in, or you could try doing these things yourself first.  I think its a fun hobby to "master" your firearm and fix it yourself.

CMMG recommends you DON'T take the sleeve and bolt apart as they can be damaged.  As you can see in the pictures its a simple matter to use a plastic tie wrap (or other method) to hold the bolt to the rear out of the way.

Bolt tied back with a plastic tie:



Now, using the proper polishing compound make it shine. Here again, a few machining marks may still be left, that is OK, but make it shine:



Several others have added some compounds they use.  Just remember you want to POLISH the parts. Don't use an abrasive compound made to clean up rusty metal or you will take material off that could damage the parts. We want to polish them, not change their size or shape.

On various firearms I have used the same tools and techniques to smooth any parts that were rougher than I thought they should be. Hammers, guide rails, any parts that rub together. In a .22 firearm that uses blow-back action friction is your enemy as it will keep the bolt from fully cycling and cocking the hammer. Ammo does also matter and low power ammo can also cause this, but this is only dealing with making everything smooth and slick.

If you have any questions, just ask. Several have added tips and suggested products.  Just remember, smoother is better!

Nice tips and write up.

forever4: I know the effort that you put into the work and this thread, Thank You. With what you've done,
this upper will be around for a long, long time. It's a Riot to shoot it now, isn't it ??? The work you did is
the kind of stuff you'd expect if the factory had a custom shop. It's great that you could do it yourself...
There's gotta be somebody here that would appreciated a tutorial some day you have time...
John edited in the tutorial and it's quite a fine job too.
Dave in Florida

Back in the old days the factory would do all this hand work. Problem is increasing labor costs it made things so expensive that people could not afford them. So, the factory does the best it can to maintain a price that people can afford. This means lots of people can afford things that would have been out of their reach not too many years back.

Look at the CMMG .22 uppers. It amazes me that they can produce such a nice product and still be able to price it where we can all afford one. But, the other side of that is they can't put a ton of custom hand work into each and every one at that price. So a manufacturer has to walk a fine line between making it as good as possible while keeping the price affordable. It takes some great engineering to design a product that is massed produced yet still can function well.  Look at Compass Lake Engineering for example.  They produce wonderful, beautiful products but how many of us can afford $1k or more for just a range plinking upper? CMMG on the other hand can sell us a complete upper for $350. Its not fair to try to directly compare the two, they are in two different classes, and price ranges!. But, if a shooter is willing to take some time and learn a few things they can do work in their home shop to make their firearms much better. They can save hundreds of dollars plus have the satisfaction of doing it themselves. Personally I enjoy the challenge and take some pride in what I can do. I think many people might be surprised by just how much they can do themselves with not much expense or effort.

As I read threads here and on other sites I see a lot of fine work being done at home by some gifted and skillful shooters. People making their own stocks, magazines, and more. Many people may think they need a lot of expensive machinery and skills. That is not always the case. A lot of what is being done doesn't require a big investment at all. What it does require is an interest, some time, and some basic tools. Its a great hobby and rewards us with the personal satisfaction of what we can accomplish. After all, sitting around in the work shop in the evening with the dog and the History channel while we polish or sand our latest creation is a pretty nice way to spend an evening. Heck, we might even pop open our favorite chilled beverage while we are at it.  Life is good!

I did exactly what forever4 said and then took 7 mags out in my backyard and every one of them fired flawlessly. I would like to thank you for saving me money and headaches, as I was going to order the stainless biolt and collar on Mon.

I thought that is what would be needed to solve my problems, so again thank you.
                                                                                                                                                scavenger16

Thanks for sharing. Isn't it nice when we can solve our own problems, and save money doing it!

good stuff, yes please add some pictures and step by step ( especially the chamber part). thanks !

Sticky!  

Thanks for the compilation.

There's also an extensive list of suggestions directed to mainly full auto operation issues (anti-bounce weight, ball detent, and such) currently on the Subguns.com website,  NFA discussion forum.  I would think that some of the suggestions apply to semi auto operation as well.

Not legal advice, MHO, YMMV, etc.

Great write-up forever4! Thanks for sharing the info with us. Pictures would be nice. Some of are somewhat "technically challenged".

So.....ive been suffering from this problem for a while now.  Ive trimmed about a 1/2 inch off my recoil spring and changed the lower springs to low power units.  It seems to feed everything but CCI subsonic ammo fine.......but CCI subsonic is the only ammo I want to shoot.  Its a suppressed 5.5" SBR and anything other than subs make some noise.  So, have you run into issues with different ammos or are you just shooting the bulk stuff all the time?

I am glad this can help people. I will post this step-by-step with pictures, hopefully tomorrow. After weeks of snow, ice, and much below normal temperatures we had warm weather show up today and I had to get busy and get some work down here at the house. I cleaned up my to-do list so tomorrow when I get back from the range enjoying my perfect CMMG .22 AR I will get out the camera and get this posted.

I understand the frustration of having any machine that doesn't work just right. I spent my working career solving problems and trying to make things work right. Its nice to be able to apply some of those lessons to our favorite hobby. I am happy if I can help anybody here in any way. I have learned a lot here myself and really enjoy the sharing of ideas here, its a great asset to us all.

pics please

i would love to get a little more reliability out of my 22

I run about eight different ammo brands in my .22 uppers, but not any subsonic stuff. In the past I have tried it just to see what it would do but its low power and didn't like to cycle the action fully. Due to cost concerns  I mostly shoot Federal Bulk in this type rifle. Due to this I never spent much time trying to make it work with the subs.  Other people have posted about their suppressed firearms and they will know more about those and the ammo to use than  I would.

Whatever you are shooting polishing up all the parts will help as it reduces friction. I had a "Brand S" conversion that gave me fits because it drug across the hammer as the bolt came back. The fix for that was careful shaping and polishing of the hammer and the bottom of the bolt. That may, or may not, help with the lower power ammo as it will help reduce the effort that is needed to push the bolt back and fully cycle the hammer back. It certainly wouldn't hurt anything to try it.

I've not had to change anything on my 5.5" It will even run Remington Subs until the ramp gets gummed up.
Something else is going on. I run the same CMMG kit in the 5.5" as I do in the 16".

It is a CMMG Kit?
Dave

This is One Hot Thread...If it doesn't get sticky'd we need to preserve the information somehow.
It'll help people out for years to come... Especially with what forever4 and others will add to it...

I'm about to head to the store now to get some polishing compound so I can give this a try.

I've had a bit of feeding issues but I haven't really had time to iron out the issues with my CMMG upper.

Hello,

I have already done this on my Spikes and it's running great, just one quick question, do you need to polish up the feed ramp every so often or is it a do once thing?

Yep, nice tips.

I want pics too!
Of the dancer!  She better be HOT!

The answer is: It never hurts. Depending on ammo and use you can get a little buildup on some. It varies from firearm to firearm depending on how smooth the ramp and the chamber were machined, the ammo, how clean you keep it, etc. So, since it only takes a couple of minutes its not a bad idea to just touch them up once in awhile. Just keep an eye on these parts and see how they are doing.

I have had some ammo that started leading up the firearm after only 400 rounds. There are days at the range, especially when I am out with friends who also like to shoot my firearms, that I have lead build-up while we were shooting. I am not one of those  people who will tell you not to clean your gun each time its out. The chamber area in particular needs attention on blow-back firearms.

I usually buzz my chambers every other range trip. The lead and gunk will build up. The chamber will just get smoother.
Dave N.

+1

You are exactly right when you say, "The chamber will just get smoother". This is part of the reason that a good firearm will actually improve with age. Its part of the "breaking in" process that all firearms and machines need. Parts will wear off the rough edges and work better. But, we do need to get the bad stuff out. Look at all that gunk your .22 ammo leaves behind. That and the lead build up needs to be cleaned out.

I just buzzed my chamber and polished my feed ramp until it looked like a mirror.

I live in the city so I can't exact test my gun here but I loaded some of my magazines and make sure my rifle was on safety, went down in my basement and aimed into my plate carrier (it's got plates) and cycled threw 4 fully loaded magazines, manually with my charging handle and had ZERO failers to fully feed and extract.

Granted this is not live fire BUT I was unable to do this before following the above tips. I knew about chamber buzzing but I never thought to polish the ramp which makes me feel stupid because we have been doing this to our aluminum framed 1911's for years to fix the very same problem!

Heading to the range around 6:00 p.m. to give it a try!

Ive trimmed almost a 1/2" off my spring and went to the low power JP springs.  It feeds plated and bulk ammo fine.  CCI sub are another story.  Still does not like those.....and they are super quiet so I really like em.  Im going to re-buzz my chamber and polish my ramp and see what happenes.

I don't feel safe using 400 grit sandpaper in my  CMMG chamber as it is already in spec and rounds easily drop in and out . You could easily take away another thousandth (.001) very quickly. Some chambers may need it but this could cause excess blow by and dirty cases in others.

I might try some Remington 40x bore cleaner/JB bore paste the next time I buzz my chamber or some mothers/flitz polish on a .22 bore more with patch around it for a tighter fit.

400 Grit sandpaper is NOT something we normally do...Didn't mean to imply that it was.  I had to do that on an .22 adapter once that was "plated" and the plating had gotten into the chamber adapter. Normally a cleaning brush is all that is needed. The one plated adapter I had was the extreme case. Your CMMG chamber is NOT plated and should not need this extreme treatment.

I use Mothers Mag Polish on a .22 bore swab.

I've used Semi-Chrome Polish with very good results. Absolute mirror finish when done
using the rightly size felt polishing tip and a dremel tool. The tip will also do the ramp..

I think the chamber in mine needs polishing.  I was shooting it last week and after about 150 plus rounds I discovered the rounds weren't going all the way into the chamber.  I discovered this when I felt a blast in the upper receiver area and discovered that the round had ruptured at the rim.  I then started looking at several of the other spent casing and discovered that they were bulging at the rim also, so I bagged them up and sent them off last week to Jordan at CMMG to see what he thinks.  
The ammo I was using at the time was Win, Federal and Remington when this occurred and it ruptured on the Remington ammo.  It should be noted that the same Remington ammo ran flawless in my Sig 522.  
I should also point out that my CMMG loves the new Federal Tactical ammo and I shot over 200 rounds of it without a problem.  I would use it all of the time, but for 22 ammo it's expensive at $21.00 for 375 rounds, when I can get the other brands for about $15.50 for 550 rounds.

I posted pictures tonight. Try this first and see how it works. I know I had some issues with mine and this procedure fixed it right up. Its amazing how much it can help.

OK! First off let me say thanks for this thread. As ShadowCop can tell everyone, I've been having some issues with my CMMG not feeding right.

Between the chamber brushing he suggested and your suggestion of polishing the ramp, my CMMG upper now feeds 100%.

I mentioned a couple posts back that after doing what this guide said, my CMMG was manually cycling just fine but I have since taken it to the range tonight too and it was also 100% when live fired. I put like 250~300 rounds threw without a SINGLE failure to feed or extract. I've probably only got 400 or so rounds threw the thing total. I was getting failure to feeds on almost every other round so it made shooting frustrating. I've gone thinking I was going to have to send it in to having it feed and extract 100% simply by following the advise of ShadowCop and forever4.

Thanks guys, thanks forever4 for the thread too!

Forever4

When you are brushing the chamber

Is it just the first couple of inches or are you brushing the length of the barrel

The chamber area is the part we are working on. Picture how long a .22 round is. We don't need to polish the rifling up in the barrel, just the chamber where the round has to slide in and be pulled out. Roughness in that area is what causes the issues as they cause excessive friction.  

Good question, I will make that more clear in the description.

Thanks for adding the pictures forever4! This is a great thread - now I just need to get off my butt and get busy. I've got a Spike's upper that shows great promise for accuracy, but feeding is not it's strong suit.

Question, are you advocating buzzing the chamber so it's completely smooth, mine has a visible raised ring a few mm inside the chamber & I've never had major ftf or fte problems.

Andy.

Another great question. The answer is NO, we are not trying to make it like a mirror in there! If the rifle is working fine, just clean it. As I have mentioned before, its all about friction, not having too much of it. A chamber may show visible marks yet run 100% when clean.. Its all in that friction thing. If the tops of the ridges are rounded and allow the ammunition to slide in and out then its OK. If you look at any machined part under a microscope it will appear to be very rough. Heck, look at the edge of a sharp knife, it will even look rough. Its all in "how rough" is acceptable. The correct answer to that is, "Smooth enough to function properly". The only way we know when we have hit that point is when the thing works right.

Now, even if it is functioning fine it will get dirty. Those rough edges will catch things and the chamber will in time get a build up of "crud" that will slow things down and cause problems. This is why we spin the chamber brush in there, just to get rid of the crud that we have accumulated. As most know, some ammos will foul it up faster than others. .22 blow-back firearms with lead bullets are not the cleanest thing ever made. So, the cleaning of the chamber is just to keep it working properly. If the chamber is good, and the feed ramp is slick, they it should feed and extract much better. Also, the feed ramp most generally improves with a polish job. This area is having a soft nose of a lead bullet being pushed against it and if it is rough it introduces friction that throws off the timing of the cycle and starts ruining our day. There are a lot of parts involved in this process, each has its function and each has problems that can interfere with the operation.

This thread will now be around for quite some time

I would like to thank forever4 for making the thread and Gloftoe (Mod of this Forum) for tacking the thread

I'll add my thanks too...

Dave in Florida

Brilliant! Simply brilliant work, thank you!

good informative thread...

thank you for this post.  exactly what I was looking for.  I got a CMMG WASP upper a few months back and it kept jamming on me.  when I would eject the round, the bullet was bent at an angle from the shell.  looks like it was getting caught on something.





gotta bust out the polish when I get back home.

This really works.  I could not get my spikes dedicated 22 to cycle consistently, and espicially with CCI subsonic.  I put a mirror polish on the ramp, trimmed my springs, put a low power spring set in my lower, polished the chamber, and added a CMMG dedicated charging handle.  I think the polished ramp, chamber, and CMMG charging handle are the must haves.

Great news!  Its always frustrating when our favorite firearms don't work right.  Good to hear you got her fixed. This stuff helps any firearm, no matter who made it. It is especially important on .22 as they are working with low power in the first place.

Enjoy!

All good tips. Easy to complete(15-20 minutes). thanks

nice article.

i have the spikes tactical dedicated 22lr uppers.

I'm gonna 'buzz' my chamber today...

i use a dremel brass brush to clean my bolt/ramp parts with and use a light coat of Remington gun oil; runs slicker 'n' snot on a greased glass door knob...

Very informative. Thank you.

glad i came across this thread. i'm gonna polish up my TacSol Upper.

every once in a while i get a jam. does it look familiar to anyone? what was your fix?

see pics below:







slushpup

Ouch.  You might want to trim a little off your spring too.  Im not familiar with the TACSOL unit, but my spikes got about 1/2 trimmed off of it and I polished the ramp.

I really like my CMMG 22 conversion. I found that you must keep it clean and WELL lubed or you will have trouble with it.

I used a piece of heat shrink tubing on my brush to make sure it doesn't go in any further than necessary. I don't quite touch the barrel with the shrink tubing. I had tried tape, but the oil makes it fall off to easily.