When shooting Wolf I do this also. I used a bore mop and J-B paste to polish the ramp and chamber on a cordless drill.
I did polish the rails also.

Great write up OP.  I have 2 dedicated uppers ( a 10 yr old Spikes and a custom build 20" heavy barrel that a bought from the EE a few years ago) and a couple of CMMG conversions.  I run mostly all ammo through them with little problems but have had my share of FTF or FTE like others.  I hadn't honestly read about this until now and wanted to thank you for the great write up.
I wanted to ad for those having problems with CCI subs, try using a Taccon pressure plug.  These are short money and will probably take care of the problem by tightening up the gap between the rear of the conversion and the buffer.  I was having problems with that ammo after not being able to get either Rem or Aguila where I live.  I tried all the tricks that have been written about and could not get CCI to work.  Finally read something about the pressure plug and for $8 I decided to try it out. It worked for me and now lets me run anything through my 22 uppers.  As I wrote earlier, I will definitely add the buzzing of the chamber and feed ramp techniques when cleaning.  OP you are right, shooting singles out of an .22 AR isn't a lot off fun.

Thanks for the info, guys! I did this to my CMMG .22 upper on a Spikes lower and my suppressed M&P-15/22. They both ran great with no malfunctions. 100 RDS in the CMMG and 150 thru the M&P

Just happened to look at this posting again today ,one thing i found out about my CCMG dedicated upper. It has a little bit of weld material on the back of it. This in turn marked my recoil buffer, in my stock so, you guys might check yours. I very carefully smoothed it off, betting it won't leave any more marks. I'll cover the old ones up with black magic marker to see if it marks it again.

A very common problem. I use a file to smooth it all out. Also, I don't know where to get them now, they use to have them at MidwayUSA, but there is a company that made a little stick on plastic piece that stuck on the buffer. It was maybe 1/8" thick and kept the adapter from marring the finish on the buffer. Not only that it kept the .22 adapter nice and snug up. You can also use the TACCOM plug piece to do the same thing.

GAWD, its been well over six years since I wrote up the original piece! I have sent thousands of rounds of .22 down range since then.

This is great info. I have had it saved in my subs for at least 5 years.

I haven't finished reading through the whole thread, but noticed that somewhere along the way it's been resurrected.  
On that note, I wonder if anyone has a way, of if the original poster is still around to update the pictures that are no longer in the first couple pages from 2011-2012???
(or if anyone has new pictures of the same procedures they have done recently).  

I am just now entering the world of 22LR conversion bolts etc.  Loving this site and thread for all these pcc and 22lr AR combinations.
 

Great thread, thinking about getting the PSA upper.

Any recommendations on a cleaning rod that is easy to chuck up in a drill?

Also, is the threading on cleaning rods and brushes pretty much standardized? I have an Otis kit with a bunch of brushes (and cables, hence the need for a cleaning rod to chuck up in a drill) and wondering if those Otis brushes will thread onto most cleaning rods.

The threading is not standardized.  I have rods from an old Hoppes kit I believe are 8-32, but the steel rods from an old service kit don't fit this brushes.  

I think any rod would fit into a drill chuck.  I use the same cleaning rods from my kit.

I’m building a dedicated 22 sbr.

I recently put together the lower for the build. Shooting in the back yard I was having issues with the hammer resetting. The gun is feeding great.

Any suggestions on a reduced power hammer spring?

When I get a FTF their is always a loaded round in the chamber but the hammer never cocks itself.

Would like for it to run subs as well. In my other sbr (pending) lower it would run CCI SV and all bulk pack I tried.

Some of you guys need to start using Imgur. 

What trigger and have you tested the lower with a 5.56 upper?

It’s a mil spec Anderson trigger. I ordered a reduced power spring kit from optics planet . Should be here in a few days.

Have not ran my 5.56 upper on it.

Try that first

Wow, what an awesome thread...

Ordered a CMMG 4.5" Kit to build a dedicated .22 LR upper for one of my SBR's.  It will be suppressed and I can't wait to receive the parts.

Thanks for the tips and understanding of what the general operating issues can be, and how to avoid them.

A while back I bought a .22 LR finish reamer for another project.  I now use the .22 LR finish reamer to clean out the build up in .22 conversion chambers instead of the buzz process.  Gets the gunk out quicker, easier, and is very thorough.  Plus such usage provides self affirmation and confirmation bias for having spent the money on the reamer in the first place.

MHO, YMMV, etc.

How do you actually use the finish chamber reamer? I have no experience with this tool so a bit of guidance would be much appreciated.

I'm not sure how a finish reamer is supposed to be used, but what I do was chuck it up in a tap handle and gradually fed it in and out of the chamber while twisting the handle.  Much like tapping threads in a hole.  The reamer was a bit pricey but I needed it to open up the chambers in a revolver that had tight chambers.  I would not buy one just for cleaning .22 chambers, though it does make scraping out any carbon and lead shavings build up quick and easy.

MHO, YMMV, etc.

Great information here.  It never hurts to polish things.

My CMMG stainless kit has given me no issues, other than it empties my mags very quickly.

I highly recommend the McFadden lightning loader.  It may be more fun to load mags than actually shooting.

I have to add that I have a JP speed hammer and yellow spring in a large pin Colt.  It will not reliably ignite rimfires.  I had to put a note on my CMMG storage box to not pick that rifle for the kit.  I also keep a stock USGI type charging handle in my CMMG go-box because the kit had clearance issues with the Gasbuster.

Hello all!

I just had to go back and check this thread. Its been ten years since I first posted it and I am grateful it has helped many people over the years.  The information in this thread applies to many firearms, not just .22 rim fires.  For the record I am still shooting that same CMMG dedicated upper I used in the original post. It gets normal cleanings and just keeps running day after day, 100% trouble free. CMMG makes a great product!

Where the hell did the past ten years go? Seems like just yesterday!

Wow ten years here was one of my comments from page one. Was true then still true now.

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

Pretty nice write up

came across this forum and this thread specifically after having issues with my dedicated AR 22 upper.  Let me know what you think of the hang on my Right to Bear bolt group feed ramp and the chamber of my 16" barrel, LOL.

https://ibb.co/jTy82gM

https://ibb.co/Pg3WV5k

https://ibb.co/DzWyWH9


Was having some FTE and some Failure to Feed (crushing the ammo).   Finally contacted CMMG and they are sending me a new barrel collar without any questions.  I also installed the Bore Buddy kit and installed the strongest extractor pin in the kit.  Fingers crossed these will help my issues.  I may have to follow OP's instructions to polish the barrel chamber and feed ramps.

I have a FA Colt M16A1 that I run a 22lr upper on and it runs perfect.
Started with a CMMG M4 pattern upper with stainless bolt with auto sear trip.
Added a rear carry handle/sight.

For this, I run 40 gr CCI mini-mag or CCI AR Tactical.
Both run equally well.

Did most of the mods mentioned here including buzzing the chamber, polishing the feed ramp, sharpening the firing pin, polishing the firing pin and firing pin channel, use a pressure plug, reshaping and polishing the bolt where it cocks the hammer, and greasing the part of the hammer where it is cocked by the bolt.

In addition to the above, I have stretched the operating spring, swapped out the firing pin spring for one from an ink pen, and finally, I polished the rails the bolt rides on as well as polished the channels in the bolt that the rails run through.
I did that by taking a putty knife and wrapping sand paper around the end of it. Then running the putty knife back and forth through the channel. I used increasingly fine grade paper until it was all very slick.

Not sure there are any other areas where friction could arise that I haven't addressed.

Using Black Dog Gen 3, Smith and Wesson MP 15-22 with the Better Mag adapter and even the old cheap Chiappa Ar15 22 magazines it runs about as slick as you can get one to run.
The Chiappa magazines surprised me.
Don't use the Smith and Wesson MP15-22 magazines much, as I don't like to mess with installing and uninstalling the Better Mag adapter.

I use the above magazines as they are the ones that have a button to assist with loading.

I don't use the bounce weight as I have had not needed it.

One thing though, if you load more than 23 or so rounds in the magazine, you start to have some problems if you do a full auto mag dump with a single pull of the trigger
I think the M16 running on .22lr can outrun the ability of the single position feed magazines to supply ammunition fast enough for the rate of fire.


Raymond

@kingoftheriver

Thank you for posting the information.

I am curious as to how the .22 upper assembly you have can operate in full auto mode reliably without the use of a anti-bounce weight (ABW) or the implementation of an alternative anti-bounce configuration such as the so-called "ball-detent mod".  I mostly use a CMMG 9 in. bbl. dedicated upper and .22 assembly including sear trip and a home made ABW on a Colt M16A1 with all mil spec FCG.  With  40 gr CCI mini-mag or CCI AR Tactical ammo I have found the CMMG ABW too light (at about 0.72 oz.) to counteract bolt bounce, and so I use an ABW of at least 0.9 oz.

The typical rates of fire I've measured using a 1 oz. ABW are around 1150 RPM with MiniMag and 1200 with AR Tactical.

MHO, YMMV, etc.  
Be well.

My bad!!!!!!!!

I AM using the anti bounce weight, but it is the one with the side cuts for use with a forward assist!!!!!!


Not the older style smooth side anti bounce weight.

I guess I was thinking of it as a forward assist adapter.



Raymond


EDIT: Haven't shot it in several years.

Here is my setup.
CMMG 16 inch dedicated upper.
Went with 16 inch so I could also run upper on my other lowers if desired.

My .556 upper is a 16 inch mid length gas system upper with 1/7 chrome lined barrel with a blem upper from someplace I forget (Brownells?)
Have been thinking about switching it to standard A2 upper and having the barrel forward of the front sight base turned down to pencil barrel profile.
Would also like to get a mid length triangle handguard, but so would everyone else apparently.






Raymond

Thank you for the clarification.  For the last several years I've made my own slick side ABWs by splitting, slotting, notching, and filing to fit Hillman 3/4x1x2 Spacers.  At $1.60 each for the spacers, one can make two 1 oz. ABWs.

MHO, YMMV, etc.  Be well.

Thank you for the tip on that last year.  I found the part, bought a couple, then spent an hour with some, tape, markers, vise, a hacksaw, file and a dremel.  I've not tested it yet, but they seem OK, much more tightly fit than commercial items.

You're very welcome.  So long as the slot in front is long and wide enough to provide clearance for the hammer to swing through its arc; the notch at the back is about 5-6 mm towards the front so that there's about 3mm of fore-aft travel; and the fit between the ABW and the recoil spring tube at the top and the receiver on the sides is just loose enough so that the ABW "rattles" without scrubbing on the inner sides of the receiver or the bottom of the recoil tube your ABWs should work as well as any that are commercially available.  I also shorten the spacers by about 1 mm at the front and back so that the rear of the recoil spring tube and the ABW are flush to the assembly back plate when the bolt is all the way to the rear to distribute the impact area on the back plate.  As well as doing a "rattle" check to ensure there's fore-aft play to get the bolt bounce cancellation effect, I dry fire test with snap caps before I check with live ammo.

Best of luck.
MHO, YMMV, etc.  Be well.

Having recently bought a used CMMG Mk4 dedicated .22LR I decided to fit an anti-bounce weight (part of a performance upgrade kit) from a UK manufacturer as I have heard only good things. It turned out to be quite prophetic as shortly before it arrived I had just cleaned the gun and was about to put it away when I found the trigger (CMC drop-in) to be jammed solid. A close examination revealed a small, roughly square, piece of plastic stuck under the nose of the trigger and the trigger casing floor. That turned out to be from the factory part, forward assist piston. Caused me a moment of consternation....


Pushed back in place

Wow! Its been just over thirteen years since I first posted starting this thread. I see its been read many, many times and I hope it has helped others solve some of their problems. There was a time, long ago, when firearm makers put more hand work into their firearms. Parts were hand fitted and lots of TLC went into the making of firearms and other machines. Higher labor costs, more overseas competition, etc. drove up prices and corners had to be cut to keep prices down where people could afford things. Its said they "don't build them like they use to" and in many cases that is very true. I hope that more shooters realize there are little things you can do yourself to make your firearms perform better and be more reliable. If this thread has helped others than I am happy and feel it was worth the time. Personally I am tankful to a friend of my father who I learned much from. He was a tool and die maker at a General Motors plant and as a hobby built fire arms, from scratch,  mostly classic black powder stuff. He also did gun repairs. He made many parts himself and was happy to share his knowledge. Later in college machine shop I followed his example and would make automotive and gun parts to do repairs and upgrades. Knowing different alloys, machining and heat treating was both interesting and helpful. Its been a fun ride all these years.
Enjoy your hobby and never stop learning. AR15.com is full of so much great information with so many highly knowledgeable folks. Great site for sure!

Stay safe and carry on.

Your thread was part of what launched my switch from 10/22s to ARs almost a decade ago.  Being able to read peoples' solutions rather than just reports of people who couldn't get their conversions to work convinced me they weren't categorically bad.

The aftermarket is much greater now and I've made my own mistakes along the way, but here is where I got started.

What impeccable timing you posted

I've been having issues with mine, I've prolly posted earlier in thread, so ended up getting new PSA bolt

Slathered with cherrybalmz and need to test

Previously it wouldn't chamber copper plated rounds like minimags

People differ on this, but I avoid wet lubrication.  It attracts grit.

A frequent feeding problem sounds like a chamber and/or magazine issue.  I've experienced the other intermittent cause of a feeding problem, a broken firing pin; it protrudes enough to keep the rim from rising into the recess in the bolt face.

Cleaned chamber based on this, or another thread, and multiple mags
Always intermittent feeding with plates

Hopefully this fixes
If not I'll buy a new barrel lol

If there is movement of the 22 LR bolt in the upper receiver you can encounter random failure to feed.  This is why the pressure plug was developed to keep forward pressure on the rear of the 22 LR bolt.   Any excess movement can zap recoil energy from the reciprocating bolt.   Polishing the chamber on a 22 LR barrel usually improves reliability.  I use Flitz on a cotton barrel mob on a short cleaning rod attached to a hand drill.  You can also buzz the chamber with a brass brush will oil or CLP using a drill, just don’t get into the lands.

Excess movement of a 22 LR mag in an AR-15 mag well can contribute to feeding issues.  Some CMMG mags had tabs on the spine of the mag.  You need to file the tabs to adjust the mags for fit.  Not all the gray colored CMMG mags had the tabs for adjusting fit.  CMMG added the detent to the collar to prevent the loose fit on the barrel stub but was still easy to remove the 22 LR bolt for cleaning.  A loose fitting collar to barrel or loose fit of the collar to the guide rails can contribute to malfunctions.   CMMG changed the length of their barrel collar and barrel stub a few years ago.  It is important the collar feed ramp matches the barrel chamber, an improper length collar can break the feed ramp off the collar or be loose on the barrel stub.

Last common issue is notched hammers hanging up in the bottom of the 22 LR bolt under the firing pin area.

Nevermind. Just saw how old this thread is.