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Posted: 9/4/2006 4:29:04 PM EDT
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Figure I'll post here for a quicker answer. Went with a few mags of Wolf to the range and a few with the IMG Guat to test out. Used proven mags and just shot it a few weeks ago with 60 rounds of Remington rapid/regular fire. So I know the AR was working a few weeks ago. All I did was add lube to mainly the BCG in that time span. First round of Guat - no extract. Same on second. Okay, checked shells and extractor, all looks fine. Rule that out. Round actually extracts but nothing is fed. Changed mags to Wolf to try different mag/ammo. Failed to extract on Wolf and different mag. Went to yet a third mag with Guat and again same thing, sometimes the shell would extract or halfway extract and jam. An observer noticed the bolt was NOT going all the way back. So now I'm positive it is short stroking. I strip down to bolt and the gas rings were kind of lined up so I stagger them just in case. I also try to wiggle the gas key but it is staked very well courtesy of Grant. It is plenty lubed. I assemble and go the rest of the original mag one round at a time manually working it. When I get to the last round I notice it extract this time but sure enough the bolt didn't lock back. That confirms it. I disassemble and the gas rings are kind of lined up again but I seriously doubt that is the problem since the problem happened on the first round after I checked. I stagger again and run 2 rounds through and have the same problems and no lock back on empty mag. I check gas rings again and they've stayed staggered for that quick test. So to recap - gas rings staggered, key staked, tube looks unbent, both types of ammo failed (underpowered .223 and hot 5.56,) 3 proven mags failed, buffer spring has been used before just fine so I don't think that is it. I think everything is good to go except the gas tube. I seriously doubt gunk is inside it so I'm guessing the problem lies under the gas block. I won't have time to get to it immediately but just want to hear what y'all think. Thanks guys. (DSC lower with RRA 2 stage trigger, BCM upper. I think the BCG is LMT M16 bolt. Everything has worked fine prior to this outing using WWB and Remington. This is the very first Wolf and 5.56 I've had to run through this. EVERY single round was manually fed.) Less than a thousand through, 4 rounds total of Wolf. Gast Tube Observations - The front hole has a pattern of carbon around it that is very uneven. Assuming the roll pin side is 12 oclock there appears to be carbon eminating from 5 oclock. http://www.razoreye.net/pictures/gasblock1.jpg http://www.razoreye.net/pictures/gasblock2.jpg http://www.razoreye.net/pictures/gastube1.jpg http://www.razoreye.net/pictures/gastube2.jpg http://www.razoreye.net/pictures/gastube3.jpg |
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Ideally, with the rifle reassembled, go back and re-fire the rifle with the proven rounds that function is the rifle before. This will confirm if the problem is ammo related or other. Now the one item that is more suspect beyond the ammo selection, the round count, the manufacture of the upper, is your uses of the words "the carrier key has been staked". Staking alone will not guaranty that the Allen head bolts are still tightened to the specified 35 in lbs of torque, and the bolts should be checked to verify that they are correctly tighten in lien of them being staked alone. Furthermore, to point to just the upper assembly alone, the bushmaster barrels are known not to function with wolf ammo until the barrel (chamber) has been broken in through live fire. With the statement of less than a thousand rounds through the rifle, this point of the chamber surfaced being gilt has yet to be achieved. As for the Guat ammo, with the case conditions of the surplus ammo being often less than commercial factory fresh, and again, the state of the chamber being less than epitome, this alone could be the problem that is arising with such ammo. To surmise, after you have checked the above-mentioned areas, have retest the rifle with the known working type ammo, if need, get back to us and if you can, a photo of the chamber conditions would also be of importance. |
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