Major problem with new CMMG 22lr

So its all CMMG brand name made dedicated 22lr ar 15 rifle

From the second we got it off the wall at the gun store the bolt was jammed. Ended up being that block for the forward assist rubbing somehow. I had forced the bolt out of the upper with the charging handle and that block came flying out. I was able to put it back in after looking at you tube to even see how it fit, and it freed up and hand cycled great.
Day later we took out the bolt to oil it, and look it over and was not able to get that block back into the rifle without the jamming again. Would not close.
So instead of messing with it anymore I took out that block. Since my spikes bolt never had one I know it will work without it.

Went shooting today.
I think the first 2-3 mags ran perfectly
After that jam city. I think its called short stroking. Not enough energy to flip the hammer back. Now all that time we were only using american eagle 40 grain I think. So we cleaned it, reoiled it and ran winchester super x. I think its 36 grain. Still the same thing. Would not cycle the next round.
Used 2 mags, a well worn black dog and the new cmmg mag it came with. Its not mag related as even single shot no mag the hammer does not go back.

Now I have about 10,000 rounds through my original spikes conversion bolt and in the beginning I had to do alot of work, polishing, filing, clipping the recoil spring I may have even used a softer hammer spring I cant remember.
But I would assume the CMMG made dedicated rifle would somewhat work out of the box. We never got it to run more then 1 round at a time hand cycling it. Gave up after 4 mags.

I did not bring my ar conversion out today, because that would of been perfect to test my lower and the cmmg upper on mine.
So any idea whats up. Why it shout 2-3 mags perfectly then after that only 1 at a time.
I feel no resistance when hand cycling the bolt, but im not sure if something isnt correct as we were never able to get that forward assist block back in without having the bolt stick open.

...

it sounds like there are two issues. if the forward assist isn't installed correctly it will do exactly what you are describing. for the short stroking all the chamber needs is a buzzing. buzzing the chamber is something i do after every outing. The good news is that both things are easily remedied. It is frustrating when it is the first time out. You will be up and going in no time. btw, you can view the buzzing procedure on the CMMG youtube channel.

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Told him the same thing on Calguns

I kept the forward assist out during the shooting, as I could not get it in the day before
but I will look at the video I found showing how it goes in since I had only put it in once, im pretty sure it only goes in one way
but from the factory, or whoever shipped it to my gun shop the bolt was jammed open even on display

let me look over it tomorrow and watch the buzzing video before I call, since its my dads rifle anyways he can test shoot it maybe tuesday or wednesday and then I will see if it fixes it

They will get it straight. I have one of the first dedicated 22lr rifles that I shot approx. 5000 rd without cleaning(my own litte test), it and my SCAR17S have become my favorite rifles

I will also try to get some good closeup pics before I clean anything
even though it was semi cleaned on site and re oiled I do remember seeing some particles later
http://www.youtube.com/watch?v=QKfBoWJh_RU

I did that buzzing on my old spikes bolt, but with a pad around a small drill bit
But when I had a part start to break from age they sent a new bolt out, I have done nothing to it yet and its ran at least 2000 rounds
No spring adjustments, no polishing, very little oil
Only because I was out of the ar game for so long I had forgot what I did to the old bolt to get it to run so I never did any work to the new one
I can tell the difference in metal the spikes seems more slicker
the cmmg seems more rough I guess
otherwise looks identical

Ok I did place the forward assist block in the rear, which caused that jamming problem a few days ago
So problem solved for that one.

But the more important problem
I had removed the forward assist block during the shooting trip where the hammer would never catch back after a few mags of running great. I dont think there is a chance anything got too dirty to cause this problem.


Since this is a dedicated rifle, how do I buzz the chamber?
So here are pics of everything

Copper 22 brush on a piece of cleaning rod and a small variable speed drill to buzz the chamber.

BTW: Great photos and write up... I can't see anything obviously wrong... And,, that is a properly
installed forward assist..

Dave S

Is the spring detent snapping onto the barrel? It's hard to tell from the pics of the collar but it looks like the spring detent isn't under spring tension. It should snap onto the barrel and take some force to pull it out of the upper.
Dave N

if you mean the little ball snapping into the ring around the barrel
yes

but you see how super dirty that area is, im wondering if its not making a real seal and that extra gas is blowing by
less then 60 rounds there but its so dirty



is the hammer the correct type too

The hammer is fine. Dirty ammo is always going to create problems faster. That is why we recommend the copper wash.
Dave N

yeah but a few mags then jam city
I cant accept that when I use the same ammo on my spikes and can blow through a brick in one outing with no cleaning
ive used at least 10 bricks of both american eagle and winchester super x lead tipped and never had problems
maybe it needs broken in but I still have it in my head its a dedicated 22lr store bought, it should work pretty good out of the box
at least one would think


I can understand problems with a drop in conversion


but I got it really clean and oiled up ready to go for today
hopefully it works

So I did a full detail cleaning and oiling
I noticed the hammer area was bone dry and gritty so I put a drop of oil on those levers that catch the hammer

We were able to shoot 180 shots in a row, maybe 2 hammer issues and 1-2 stove pipes
All on video
I know we surpasses round count from last time, so either it needs to be broken in more, or it could of been something with the dryness of the hammer not really sure im no ar expert.
But im satisfied it will work better now, after more use. My dad was happy.

Make sure you buzz out the chamber after each use. This is the one thing that will make your rifle run better than anything.

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So you can buzz the dedicated rifle too
the video I saw only showed the conversion bolt
I just didnt want to purposely wear out the real chamber

But if you say its cool then I will have my dad do that

Do you use nylon, brass
oil?

Your problem is not unique nor is it likely serious. Go look here to see how to do this job, step-by-step with pictures (no video);

How to buzz the chamber on your dedicated .22 rifle

And if you are unhappy with your CMMG upper, I will gladly trade you for a Tactical Solutions one I have.

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