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Posted: 12/7/2009 5:06:55 AM EDT
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I was getting a jam in my M4 this weekend. After I fired the next round would chamber about half way. All the ejected rounds were bent; it was denting the brass and bending the bullet,(which is why it didn't chamber fully). I would spray a ton of oil in the chamber and it would operate fine.
Is this just an example of a gun that needs to be run really wet? Or do you think there is an underlying problem I need to correct? |
| I would not recommend spraying a ton of oil in the chamber. Sounds like your chamber is dirty, because after its lubed it works again. I would scrub the hell out of the chamber. What kind of ammo are you using? If its not ejecting it could not be getting enough gas, if this is the case you would need better ammo or open up your gas port a little more. |
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I don't think I explained it correctly. I chamber the first round and it fires. The next round is feeding half way into the chamber. I have been ejecting that round that only chambered half way and inspected it and that is when I noticed the bullet is getting mangled loading into the chamber. It's like the bullet is catching on the feed ram somehow and bending it.
The gun was cleaned before shooting, as well as the chamber cleaned with a chamber brush. Bolt Carrier sprayed with oil before shooting. I'm not filling the chamber with oil but more spraying the feed rams (spraying toward the chamber is what I should have said). I'm shooting Federal Bulk pack ammo (Wal-Mart special). |
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Do you have the proper buffer and spring? is it a build or factory rifle? I would not worry about the ammo as an AR should shoot all types including steel cased ammo. Maybe a gas leak as mentioned above. Gas leak is a real possibility. I do have the proper buffer and spring, although I might switch out springs just in case. |
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Quoted:
Quoted:
Do you have the proper buffer and spring? is it a build or factory rifle? I would not worry about the ammo as an AR should shoot all types including steel cased ammo. Maybe a gas leak as mentioned above. Gas leak is a real possibility. I do have the proper buffer and spring, although I might switch out springs just in case. If it is a factory rifle that is problably not an issue .I was thinking using a carbine buffer in a rifle tube could possibly cause issues . Look for a gas leak around the front tower . I believe there is a trouble shooting forum on this site might want to post there .Good luck |
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If this is a new carbine, I would say run it wet. It might just need some more rounds through it. I had a problem similar to yours and if I ran that armalite wet, I would not have problems any more. After a few hundred rounds the problem went away.
Good luck! Posted Via AR15.Com Mobile |
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Since you're using quality ammo and you've tried four different mags, I'm betting on a gas problem.
Does the bolt lock back reliably after the last round is fired? If not, your rifle is likely shortstroking. While there are a stlll a few other things it could be, that seems most likely to me. Best fix is for the manufacturer to see the rifle again. |
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Pmags or metal mags? I would guess your failure to feed issue is mag related. If you don't have full M4 feed ramps, the position of the tip of the bullet in the mag in relation to the feed ramp is much more critical. All metal mags. A Colt, a GI, and 2 AR stoner mags. |
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What I found in my case, that there needs to be atleast an 1/8th (.125) of an inch between the top of the leading edge of the metal mag and the tip of the bullet. I had a H&K mag that I had FTF issues, the retaining lips that hold the rounds were holding the bullet too low and the tip of the bullet would not hit the ramps correctly.
PMAGs are designed to pitch the round upward as it feeds, metal mags do not. I would try a PMAG. But be warned PMAGs are a bit snug in many magwells.Especially Superior Arms lower receivers. |
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