Posts: 194
Threads: 19
Joined: Mar 2011
05-12-2011, 06:09 PM
(This post was last modified: 05-12-2011, 06:11 PM by skyfish.)
I had my first issue with feeding rounds from magazine. Mine looked very similar to other post and I am leaning to ejector too long.
The cartridge strips from mag, and stops short. With a drag mark on the brass on the lower side, almost a half moon looking scrape. Acting like the rear of the cartridge can't rise fast enough for a smooth feed. Happened on both my factory Hornady and reloads. Worse from right side of mag(as looking down the rifle to shoot).
Is there a correct length?
Oh yes, it is an AA barrel and bolt. I ordered it in March of 2009. Yea, it took a while, but so did everything back then.
These are the things I would start looking at to try and trouble shoot the problem:
1. Ejector too long. Use a case, and with the bolt out of the rifle, see if you can easily get it to snap under the extractor and seat properly into the bolt's recess. If it will do this, the ejector probably isn't too long.
2. Extractor has too much tension on it. If there is too much spring power on the extractor, the round can't snap in under the extractor. Check this again with the bolt out of the rifle, and see if the cartridge easily snaps under the ejector.
3. Burrs on the inside of the magazine's feed lips. These burrs cause excess drag so the round can't be released to feed properly.
4. Make sure you don't have an M4 receiver with standard rifle extensions cuts in the barrel extension. You have to have either M4 ramps, and M4 barrel extension, or standard ramps, and M4 barrel extension. If you have M4 receiver cuts with a standard barrel extension, the bullet nose can hang up and not feed correctly.
5. Try the rifle out with only a few rounds in the magazine. Sometimes if there are too many rounds jammed into the magazine, the bolt doesn't have enough forward power to strip the top round off the loaded magazine.
6. Look for really sharp edges on the edges of the barrel extension's lugs where the bolt locks in. I'm not advocating grinding away at the barrel extension's locking lugs, but look for something that will cause a hangup in feeding.
7. Insure that you have the proper spring in the rifle's buffer tube. If you have a rifle length spring in a carbine, or vice versa, you can cause problems for yourself.
Maybe this will help you find some more information.
You can also buff the edges of the feed lips on a buffing machine, it will remove any roughness. Don't get overzealous and make sure you clean the lint out.
This reminds me that I need to get all my grendel mags back that I had loaned out, I need them for the Range event.
Last time out there someone walked off with three 26 round mags, we found them in a trash bin, I guess they did not work too well with 5.56mm.
Next time we are keeping a better eye on the line when we don't know everyone.
Posts: 194
Threads: 19
Joined: Mar 2011
Warped, your a better man than me. I tend to only lend out stuff to a select few. It seems that family is the slowest returning as well.
I'm going to reinspect the mags, the new 10 rounders are a lighter color. The original 3(26,26,17) I have were black. I just picked up 2-10 rounders from AA and the coating is different. A grey, not as light as gov. mags, but not black.
Checking the bolt last night, I may just polish the extractor as well.
The other thing you may want to look into is the extractor thickness. I had an AA extractor that was too thick. When the bolt was pushing a round forward and the extractor was over the rim, there was not enough clearance for it to get past the lugs. If I force the bolt forward, I could see damage on the rim of the case. Replacing the extractor fixed the issue (AA did this for free). I also tried dremeling some material from the left and the right of the extractor "bolt lug" to give it some clearance and that worked as well.
--Rootshot
