05-12-2011, 11:48 PM
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.
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.