Anyone still own a CMMG dedicated AR .22lr upper?

[deviljon]

Took my dedicated AR-22 out to the range the other day, but ran into a lot of problems with misfeeds, light strikes, etc.. i'd say 60% of the time it was okay, the other 40% had issues.

Just wondering if anyone still has one and if you've been able to run it consistently without problems? If so, what kind of setup/parts do you have? If not, what parts are you using?

Trying to figure out what's wrong with my rifle. Considering swapping out to an m&p 15/22 if I can't get this to run smoothly but would prefer to get it fixed before having to buy an entirely new gun.

upper:
cmmg dedicated .22lr 16" barrel with stainless collar
stainless steel bolt with forward assist


lower:
new frontier armory polymer lower with blowback hammer
BHOA - bolt hold open actuator
cmmg 10/25 gray magazines
blackdog 10rd magazines


Any input would be greatly appreciated!

[K001]

deviljon -

The cmmg .22lr WASP upper that I had was equipped with a Taccom 'reliability kit' (extractor, recoil spring, firing pin & spring, bumper) as that seems to be necessary with these uppers to function properly with some lowers.

http://www.taccom3g.com/22rf-reliability-kit.html

Hope this helps ~

[deviljon]

^Thanks! What kind of mags did you use?

[K001]

They were the cmmg 10 rounders with steel feed lips.

[readysetgo]

Maybe take out the BHO and test again, to eliminate that as a source.

[alpha_romeo_XV]

I'm not sure what you mean by a bow back hammer in the lower. I have the 20" upper and run it on a variety of aluminum lowers which have two stage triggers. Using ten rnd black dog mags and Rem golden ammo it feeds, goes bang and ejects 99%

[gatx105]

The following:

https://www.cmmginc.com/shop/upper-group-mk4-t-22lr/

http://www.redi-mag.com/index.php?l=product_detail&p=52

Lower with PSA lower parts kits
M&P 15-22 magazines

Bolt locks back every time, i shoot all sorts of .22lr through it with out any issues right now, Winchester m-22, Rem golden bullets and thunderbolt, federal auto match, CCI SV, Aguila SV and HV.

All i did was slap on the upper and i was good to go. I am not sure how other BHO kits work, but using the M&P magazines and that kit worked wonderfully, its a mimic now to my normal rifle that i use.

[readysetgo]

I'm not sure what you mean by a bow back hammer in the lower. I have the 20" upper and run it on a variety of aluminum lowers which have two stage triggers. Using ten rnd black dog mags and Rem golden ammo it feeds, goes bang and ejects 99%

There was compatibility issue with the NFA polymer hammer, an alternate hammer design claimed to have fixed it.

https://newfrontierarmory.com/shop/lw-15-complete-polymer-lower-receiver/

*NOTE: Some .22LR, 9mm and other blow back style upper receivers use a groove in their BCG that is too narrow for the polymer hammer that comes standard on the New Frontier Armory LW-15 complete polymer lower receiver. In these cases you will need to switch to a blow back style hammer available by clicking HERE. The blow back style hammer, once installed, will run all rim fire and pistol uppers, and still work fine with standard mil-spec rifle uppers.

[dieselpower]

what ammo? 36gr or 40gr 40gr is the standard to use with most blowback systems, even if 36gr "works"....

[randomBytes]

I have a CMMG .22 upper.
It worked very well at first.
The only real problem I had was with remington golden bullet - which due to shortage was forced to use for Appleseed. By afternoon of 1st day gun was so dirty it became unreliable ;-)
2nd day I cleaned it at lunch time ;-)

At that time the lower had a standard mil-spec trigger (not as bad as some but shocking compared to Geissele trigger in another lower).

At some point the original firing pin broke.
CMMG sent me a new one no problem, but since around that time I've had no end of problems with lite strikes.

I replaced the firing pin with the Taccom one, and added all their other bits,
no real improvement.

I'm currently using a Geissele SSA trigger I would say it is about 60% reliable, again lite strikes are 99% of the problems.
Actually lite strike might be unfair, they often look like they got a decent wack, they just don't go off.

A friend also has GMMG upper, and has never had any trouble with it.

[deviljon]

what ammo? 36gr or 40gr 40gr is the standard to use with most blowback systems, even if 36gr "works"....

Using the 36gr federal value pack (525 rds/box).

[dieselpower]

Using the 36gr federal value pack (525 rds/box).

yup, I had constant fails with that also. I gave what was remaining in the box to another guy at the range...I was so pissed off at it.

Use 40gr.

[Cokebottle]

The CMMG upper should come with a warning that it requires copperwashed/plated bullets.

I've not had any issues with Winchester 555/333.
Nothing but problems with uncoated, or wax-coated like Remington Thunderbolt.

I actually bought a revolver to shoot up the case of Thunderbolt that I bought.

[SonofWWIIDI]

I had a CMMG standard barrel and bolt conversion kit. It had lots of problems. I sent it back (with the upper I built for it) at least twice. They finally upgraded the bolt to the "premium" model and I haven't looked back. Lots of rounds down range, of all sorts of ammo, including the goldens. Not a problem since.

[G21Shooter]

deviljon -

The cmmg .22lr WASP upper that I had was equipped with a Taccom 'reliability kit' (extractor, recoil spring, firing pin & spring, bumper) as that seems to be necessary with these uppers to function properly with some lowers.

http://www.taccom3g.com/22rf-reliability-kit.html

Hope this helps ~

+1 I've got the Taccom firing pin and pressure plug in my CMMG .22 lr and it runs like a top. Also I have found it likes to be kept clean and well lubed(about every 1000 rounds I give the bolt/upper and barrel a good cleaning.)

Also you want to be sure to use a trigger with a full power hammer spring, I have had good luck with the ALG ACT in mine, nicer pull than a standard mil spec trigger but not too pricey.