 semperfiws6
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Posted: 8/14/2012 2:24:07 PM
THE IMAGE ABOVE IS A PAID ADVERTISEMENT Even when I "walk" the charging handle/BCG forward, it just pushes the bullet tip against the shoulder before the round even strips clear of the mag feed lips. So, I want to send the barrel back but would like to give them as much info as possible about the issue. Is there a way I can measure this? Is there more I could do/test? |
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ariesfromhell
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Posted: 8/14/2012 3:06:35 PM
by "shoulder" do you mean the barrel extension or feed ramps?
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Posted: 8/14/2012 3:09:51 PM
So the bullet tip is hitting the end of the actual barrel inside the barrel extension? Generally that's a magazine problem. Is it hitting above the chamber, or to the side?
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semperfiws6
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Posted: 8/14/2012 3:25:55 PM
Originally Posted By Gamma762:
So the bullet tip is hitting the end of the actual barrel inside the barrel extension? Generally that's a magazine problem. Is it hitting above the chamber, or to the side? Yes, the end of the actual barrel inside the extension. It hits right above the feedramps on the bottom. I have tried several mags and that is not it. Other known good barrels/uppers do not have the problem. When chambering slowly/walking the CH forward, it never pivots up and off the magazine feed lips, like the part it is hitting is to close. Same mags, lower and upper, but different barrel, the mags allow the bullet to move forward enough to pivot/angle up the bullet to feed correctly. |
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Dano523
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Posted: 8/14/2012 4:17:33 PM
[Last Edit: 8/18/2012 7:03:13 PM by Dano523]
When you where swapping barrel, did you get a chance to compare barrel extensions to see the difference there.
Also, how different is the chamfer on the two barrel breach faces to the chambers? If one barrel is having a feeding problem and the other not, then it has in the barrel/barrel extension differences . |
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semperfiws6
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Posted: 8/14/2012 4:36:59 PM
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. Could it possibly be a headspace issue? All I have is a Colt Field gauge, but if the headspace was too short, could that be an issue? |
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Posted: 8/14/2012 6:56:38 PM
Originally Posted By semperfiws6:
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. Could it possibly be a headspace issue? All I have is a Colt Field gauge, but if the headspace was too short, could that be an issue? No. The cartridge isn't even in the chamber, it never gets to headspace. Any chance the barrel has had feedramps dremeled/recut or anything like that? I'm not seeing how it would even be possible for bullet tips to hit the barrel below the chamber. As the cartridge comes forward it should pivot up a little, the bullet tip goes into the feedramp and slides up, at that angle it will go into the chamber. About the only way I can see a bullet tip hitting below the chamber is if the feedramps have been milled down too much in some attempt to make M4 feedramps or something. |
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semperfiws6
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Posted: 8/14/2012 8:54:33 PM
Originally Posted By Gamma762:
Originally Posted By semperfiws6:
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. Could it possibly be a headspace issue? All I have is a Colt Field gauge, but if the headspace was too short, could that be an issue? No. The cartridge isn't even in the chamber, it never gets to headspace. Any chance the barrel has had feedramps dremeled/recut or anything like that? I'm not seeing how it would even be possible for bullet tips to hit the barrel below the chamber. As the cartridge comes forward it should pivot up a little, the bullet tip goes into the feedramp and slides up, at that angle it will go into the chamber. About the only way I can see a bullet tip hitting below the chamber is if the feedramps have been milled down too much in some attempt to make M4 feedramps or something. The ramps have not been screwed with at all by me, and it came to me brand new. |
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ariesfromhell
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Posted: 8/15/2012 7:21:51 AM
pics my man.
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Posted: 8/18/2012 12:54:51 PM
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. This makes the most sense. |
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Dano523
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Posted: 8/18/2012 7:20:54 PM
Originally Posted By dep4532:
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. This makes the most sense. And all this time, I thought my English was getting so much better. 
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Posted: 8/18/2012 7:50:46 PM
Originally Posted By Dano523:
Originally Posted By dep4532:
Originally Posted By Dano523:
When you where swapping barrel, side you get a chance to compare barrel extensions to see the difference there. Also, how different is the chamfer on the two barrel breach faces to the chamber? If one barrel is having a feeding problem and the other not, then it has to in the barrel/barrel extension. This makes the most sense. And all this time, I thought my English was getting so much better.
I understood the first sentence...kinda' 
Common sense would dictate that if the gun was GTG, then a change was made and a problem arose, changing back would be the logical thing to do to isolate the issue. Possibly a short barrel extension on the replacement? |
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