Problem with my new upper.

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[ARCHIVED THREAD] - Problem with my new upper.

Posted: 10/26/2006 5:35:29 PM EDT

I am having a feeding problem with my new CMMG upper. My problem is similar to another poster's problem but is the opposite. The rounds are getting stopped on the feed ramps. It happens a lot during cycling the rounds manually, but few times during firing. It has polished m4 ramps.

The BC touches the gas tube but it doesn't seem to move it so I don't think that is the problem and the carrier key is not loose. Mags are clean. What the hell is going on here?

EDIT: it can happen before the key even reaches the gas tube.

Posted: 10/26/2006 6:25:22 PM EDT

[#1]

Pics would be a great help to diagnose this one. I need to know exactly where the cartridge is getting caught on the ramp. I had a similar problem but fixed it.

Posted: 10/26/2006 6:31:44 PM EDT

[#2]

try a few different mags?
First round of 30? last round in mag?

Posted: 10/26/2006 10:22:30 PM EDT

[#3]

Quoted:
try a few different mags?
First round of 30? last round in mag?

Sorry I don't have a camera right now. The rounds get hung up in the middle of the bullet, leaving nasty gouges. It happens almost every round. I rubed my fingernail on the feedramps and they feel like raw unfinished metal. Maybe they forgot to polish them? It happens with any mag.

Posted: 10/27/2006 2:00:30 AM EDT

[#4]

Call Jeff at CMMG. He will make it right. If they forgot to polish the ramps then you can do that or have Jeff do it. He will make sure that it is working 100% before it's sent back to you. CMMG has awesome CS!

Posted: 10/27/2006 5:05:28 AM EDT

[#5]

I never own CMMG But hear they are Good to go and are good guys to deal with!
I would call them FIRST before listening to us

Posted: 10/27/2006 5:09:12 AM EDT

[#6]

Quoted:
I am having a feeding problem with my new CMMG upper. My problem is similar to another poster's problem but is the opposite. The rounds are getting stopped on the feed ramps. It happens a lot during cycling the rounds manually, but few times during firing. It has polished m4 ramps.

The BC touches the gas tube but it doesn't seem to move it so I don't think that is the problem and the carrier key is not loose. Mags are clean. What the hell is going on here?

EDIT: it can happen before the key even reaches the gas tube.

Does it feed
or is it just scratching the Bullets up

getting stopped on the feed ramp?

My Bushmaster did this! But it was because of the 10rd MAG they made back then?

also sometimes Brand New AR15 need broke in 1000rds

good luck

Posted: 10/27/2006 8:08:11 AM EDT

[#7]

When I read your topic I thought you meant an upper denture!here
Thank you.

Posted: 10/27/2006 1:31:13 PM EDT

[#8]

try opening up the feel lips a little on the mags.

Posted: 10/28/2006 1:12:53 PM EDT

[#9]

I had to take some material off one of the reedramps. There was a sharp edge on the barrel extension. I then polished the ramps with 2000 grit sandpaper. It feeds 100% now.

[ARCHIVED THREAD] - Problem with my new upper.

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