Dedicated .22LR upper issues

[Canderson]

I recently put together a Cmmg .22 rifle to replicate my 3 gun AR (in hopes to practice a little cheaper).

I have a CMMG 20 inch bbl, Cmmg SS bolt and SS coupler.

I have not got it to run good yet. I polished the feed ramp a little (it looks mirrored now) I also tried the Wire brush on a drill in the chamber. I have also polished the top of the bolt release and the top edge of the hammer.

So far I had one mag run through it reliable, with maybe one failure to feed the next round (out of 32 rounds).

Then with the same ammo and same mag I had failures to load the next round, then when it would load the next round and fire the hammer would not reset. It also feels like the face of the bolt doesn't always slam all the way forward.

I've tried CMMG mags and Black Dog mags with about the same results.

I have tried numerous mags of CCI mini mags as I have found they are usually pretty reliable.

Anyone have any other ideas?

Edited March 10, 2015 by Canderson

[PKT1106]

When I had a 22 AR, I too, had a CMMG upper. I emailed the people at CMMG and they informed me that 22 ammo has a lot of variance of bullet profile from company to company. They suggested using CCI standards or Federal bulk packs. They said some profiles, most notable Remington Goldens, were finicky for usage.

I would suggest to try finding CCI Standard Velocity or Federal Bulk 22lr, maybe Winchester 333 packs and try those before throwing it off a bridge.

[Canderson]

Thanks for the info,

I tried some Federal Bulk 22, same results. I have some of the Auto match that are made for these applications I will try them next.

[3GLewie]

I have a CMMG 16" upper on a PSA lower with miss matched parts from all over. I have probably put 3-4k rounds thru it with very few failures (probably less than 10). I have tried just about every kind of ammo out there and everything has worked well. I have never "buzzed" the chamber, polished anything but the trigger, or honestly cleaned it more than a few times. Once last year before a Tac .22 match I ran a bore snake thru it and wiped down the stainless bolt then re lubed everything. Zero failures in the match using Winchester 333 bulk pack ammo.

I have used the Black Dog Machine mags mostly since I built it. Ran a few CMMG mags thru it and functioned fine with those also. I did notice that you said you had 32 rounds from one mag function well. I have never loaded more than 27 or 28 rounds. My brother has about 10 BDM mags and never loads more than 27, some are probably some of the original ones made by BDM. He was a tester for them when they introduced new mags. He has 2 CMMG uppers and they both run well. My guess is over loading the mags has damaged the springs, since they are only supposed to be 30 rounders from the factory. They aren't heavy duty springs like in a 5.56 mag.

I assume you were only having fail to feed issues, since that is what you mentioned. No light strikes, fail to eject, or stove pipes? For more info on dedicated .22's you might check out. http://www.ar15.com/forums/f_3/15_Rimfire_and_Pistol_Calibers.html there is a ton of info on dedicated .22's. ...hope this helps[emoji41]

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Edited March 11, 2015 by 3GLewie

[v1911]

BDM has since come out with 32rd mags.

[3GLewie]

Oops didn't realize they had a 32 rounder now. Haven't been shooting much.22 since you can't hardly find it now.

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[iainmcphersn]

Do you have a notched or round top hammer? I had issued with mine until I went to a round hammer. Since have moved to a RRA 2 stage trigger that it likes.

[Canderson]

Thanks for the info, yes these were the 32 round mags. In hindsight I don't think I even had 32 rounds in them, most of the time I would put 10 or so in at a time to see if I could get 3-4 rounds to function in a row.

I actually had more than a few light strikes, but it almost always ejects.

I have only had one or two stove pipes (I consider that almost par for the course with .22 though).

I will look at the hammer again, but I am pretty sure it is round. I also just realized I have not tried it on my other lower with a JP trigger, maybe that will help.

Thanks Again for the info guys.

Edited March 11, 2015 by Canderson

[Canderson]

I just checked the hammer again it is rounded.

From looking at some info on several different sites I read that the Bolt catch may be hanging up.

I took a very small amount of material off the top edge of the bolt catch with the Dremel and then polished it to a mirror finish.

That seemed to fix most of the resistance I felt while pulling the charging back/cycling the bolt. There is still a slight increase in resistance when the bolt hits the hammer and pushes down (not sure how much would be considered normal).

It still feels like it will take a pretty good force to completely cycle the bolt and re cock the hammer (like more force than the .22 provides, possibly).

[EkuJustice]

When I ran one I used the taccom reliability kit and had no issues

Edited March 12, 2015 by EkuJustice

[Canderson]

It took me a while to finally put this kit in(by the looks of the date I started this thread, a year ago), but it looks like it solved all of my issues. This thing runs like a sewing machine now. I have run several brands of ammo with no issues!!

In the end I think it was the firing pin causing all the issues.

Thanks you all for you input!

Edited March 27, 2016 by Canderson

[zzt]

It is as scarce as hens teeth, but CCI's 22 AR Tactical ammo is great stuff. It is designed specifically for AR style platforms, but works well in pistols. http://www.cci-ammunition.com/products/detail.aspx?use=5&loadNo=0956

[Steve RA]

From what I've seen and also what has been reported, all CCI .22 ammunition in the N. Texas area has really been rare.