AR Sponsor
Posted: 10/20/2005 2:36:42 PM EDT
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Got a AR10A4, ss barrel, have been trying diffrent point to rest the forearm, zeroed with the rest at the delta ring and when shooting with the rest further out on the forearm, the group moves up about three inches, is this normal? barrell nut problem? Am looking at the FF tubes, like the the look of the JNP FF tube for the smaller Dia. knurled version, any experience with this version. Edit; Real question is is there a noticable diffrence in POI when the standard handguards are used when the front of the rifle is rested close to the front end of the handguard vrs the rest at the rear of the handguard? Is this normal with the AR style of action? |
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Unless your leaning into the rifle and putting a lot of downward force on the back of the rifle to bent the barrel, I would say that the barrel nut is loose. Not the end of the world, just pull the gas tube, chuck the upper receiver in a vise block, then tighten/loosen/tighten up the barrel nut more than 35 ft lbs, but less than 80 ft lbs. If you don't have the tools, then drop Aramlite a call, I'm sure they will resolve the problem for free. |
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Don't have the tools, and just got the rifle back from Armalite, for the NM trigger replacement,(rifle went Full auto) weak disconnector spring. Don't guess that the barrel nut would have been checked for the trigger problem. Hate the idea of sending the rifle back just to check the barrel nut. Don't think that I am leaning that hard on the rifle. Want the FF tube anyway, was just wondering if the shift of the group is this noticable in the AR style rifle. |
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With a loose barrel, yes. Also, I have to ask this question, When shooting bench, your weak hand should be under the butt stock, and you should not force the rifle down (let it recoil). If you have been pinning the rifle to the bench with your cheek, and using you weak hand on the forarm to apply even more pressure to the middle of the rifle, you may be the one deflecting the barrel, and it may not be loose. |
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I installed a FF tube on an AR10 for a customer, the barrel nut on that upper was tighter than any I have ever battles, had the DPMS wrench with a cheater pipe on it to get it to break loose, when it broke loose the sound was such I thought I would be buying a new upper receiver. It sounded just like the upper had cracked in half. Anyway the facotry Armalite FF tube was very easy to install and index once I figured out how it works. |
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