Motiuk upper bolt jamming in barrel help

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rockready69

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Ok so I bought a motiuk upper from another CGNer new never used I wanted to swap it out with the NEA upper I have so my motiuk lower would have a matching set enyways I have only shot 200 rounds out of my new upper with no problem once swapped the uppers out my WMD Nicole bolt lugs catch on the barrel it jams once its in and won't come out with out force I've checked the gas tube its aligned seems like the bolt it catching on the bottom of the barrel i swapped the barrel back over to the NEA upper and no problem any ideas guys
 
If both uppers were done according to spec then this shouldn't be happening...but if the new one is slightly out of spec? I've had a similar issue to you in the past but in my case it was a problem with the bolt itself.
 
rockready69 said:
Ok so I bought a motiuk upper from another CGNer new never used I wanted to swap it out with the NEA upper I have so my motiuk lower would have a matching set enyways I have only shot 200 rounds out of my new upper with no problem once swapped the uppers out my WMD Nicole bolt lugs catch on the barrel it jams once its in and won't come out with out force I've checked the gas tube its aligned seems like the bolt it catching on the bottom of the barrel i swapped the barrel back over to the NEA upper and no problem any ideas guys
Click to expand...

So it's the same barrel on both uppers, but it will jam up when the barrel is on the Motiuk upper.
My guess is the alignment notch on the upper for the barrel extension pin was cut too big or off center, so your barrel is sitting crooked in it.
 
I would,

try another bolt

remove barrel, inspect and measure the diameter and depth versus your other upper

if all looks well re-install and try again.. maybe a different barrel nut? Tighter/looser torque of said nut..?

Lastly, try another barrel on the problem upper if possible before you write it off. Within the narrow range of tolerances I find you can sometimes get two parts that are less than ideal in fit.

My bet is on the barrel not sitting deep enough in the pocket, and perhaps the bolt is setting up TIGHT against the barrel lugs when sprung forward into battery, making it very hard to manually open. You can check this by getting a candle or felt tip marker and blacking up the bolt lugs, once re-installed and operated you can see where the contact points are.

It will give you an idea anyway... Maybe the upper pocket is not true, and is a wee bit crooked.

just thoughts for you to chew on...

good luck

EDIT:
Curious.. how are you clamping your upper to be able to remove barrel nuts and such? Are you using a jig.. if so what type? Some jigs I have seen were better than other for these jobs. I purchased the Brownell Barrel Extension Torque Tool and never looked back. Mucher cheaper than the Geissele Reaction Rod

youtube.com/watch?v=n4Y_JrfDcXU
 
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It's not the bolt bolt is good have only shot 200 reds with it it seems like it's to tight and binds on the bottom of the barrel and like I said it works great with the NEA upper and barrel so has to do something with the Motiuk upper ....I tried loosening the barrel nut and it dosent jam but soon as I torque the barrel nut up it starts jamming I've contacted Motiuk hope they email me back with some info ....this is my second Motiuk upper I have purchased first one had no problems sucks all I wanted is a batch set

And I'm not to sure what brand the jig is that I'm using the barrel wrench is a wheeler
 
Maybe the original owner of that Motiuk upper warped that upper when they tried to install a barrel, realized they f'ed up and sold it to an unsuspecting buyer? Sight down the length of that new upper. Does it look slightly warped?
 
Trinimon said:
Maybe the original owner of that Motiuk upper warped that upper when they tried to install a barrel, realized they f'ed up and sold it to an unsuspecting buyer? Sight down the length of that new upper. Does it look slightly warped?
Click to expand...

That is where my mind was heading ... :)

or that barrel was too far in.. or not far enough. Understanding now that it binds when barrel is torqued,.. leads me to think it is not straight in line (warped/twisted/angled). I would pull out the digital calliper and measure the pocket depth and the depth of the barrel pin notch just to rule that out. These could be shimmed to move your barrel out a thou or two if the lugs are binding...

or maybe even a little valve grinding compound on the lugs IF that is the issue.. work the bolt a little.. It MAY just be one or two lugs! Try the marker or candle (soot) on the bolt and see where it rubs...

I guess the first and most obvious thing I would do is pull out my headspace guages to see what that reveals. But most people don't have these hanging around.
 
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So got the info back on my upper sounds like NEA barrel is the problem the barrel extension pin seems to be off aparetly I guess NEA stuff can't be used with other uppers .... Motiuk is going to give me a deal on another barrel hope that fixes my problem
 
Always good to see how things end up with their customer service. Keep us informed. I'm always interested in supporting Canadian sources for AR fun. Well, canadian businesses also!! :)

Cheers and keep helping the noooobs out there!

Barney
 
rockready69 said:
So got the info back on my upper sounds like NEA barrel is the problem the barrel extension pin seems to be off aparetly I guess NEA stuff can't be used with other uppers .... Motiuk is going to give me a deal on another barrel hope that fixes my problem
Click to expand...

That's weird.. I used an NEA upper with another manufacturer's barrel no problem. Unless their uppers are manufactured not to accept their barrels?
 
remove the barrel from the upper and strip the bolt from the carrier, now remove the extractor from the bolt and check to see if anything is jammed under the extractor and the spring/o ring are in place. take bolt and insert it into the barrel extension as if it were going into battery, give it a rotation to "lock it up" watch that the lugs on the bolt hide behind the locking lugs on the barrel extension. try it with and without the extractor in place on the bolt.
 
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