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Posted: 6/3/2004 11:03:38 AM EDT
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Im using a new carrier that seems ok except for its lack of finish. Im using it in a old upper and when I insert it it gets tight about a 1/4 way and then loosens up some but there is no free movement on its own. Is there a break in for new bolts or is something out of spec? Thanks |
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Since the only areas on the carrier that touch the upper receiver are the upper/lower guiding tracks on the front of the carrier, and the sides of the key to the upper slot, my guess is that the either one of the guides or the sides of the key have a bur that needs to be removed. Note: This is only if the carrier fails an open upper slide test. If the carrier moves freely in the upper alone, but binds up with the upper/lower mated, then my guess would be that the hammer tail is too long and the hammer is binding up on the top of the disconnector. To solve this type of problem, then you would just need to remove .040 increments of metal from the hammer tail until it no longer binds. Note: It also helps to confirm that the disconnector is retaining the hammer during the re-charge cycle, and that the hammer is not being freed/released and is what is causing the binding to the carrier. |
Sorry Tweak, Finished up last night NM'g the HRA Garand parts (just receiver it from CMP last week), and am now waiting for Boyd to get mail me the laminated stock I ordered a few weeks ago to mate/glass the whole thing in. I had nothing better to do after power shopping with the wife for new complete front room furniture set and a new spare bed/computer room set (nothing like buying a new house and having the wife tell you that that the old furniture has to go). Had to get the taste of dropping $3200 on the two rooms out of my mouth, and just got to the site instead of taking my afternoon nap. Trust me, I only get to be on holiday for another week, then it back out on the road. My guess is that you will beat me to a lot of posts really soon (by days). --------------------------------------------------------- Rob, You just need to check the guides and sides of the carrier key to see where it is binding. If needed, just smoke the dry parts with a Sharpie marker to see where the binding is accruing. The areas that have the marker remove will be your problem areas (my guess is that is the 4 corner sides of the key that are binding). |
S'cool D, I'll spend a little more time loitering in the area then. Rev-Rob, The problem most likely lies in the carrier key if the upper is known good. The key is the only snug fit in the upper. Just to double check, you're using a stripped (no bolt or cam pin) carrier to test? |
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Possibly the upper is bent. This happens sometimes when a barrel is changed, and the upper is put in an action block without the insert, but it can happen other ways. Usually they bend even with the rear of the ejection port, the weakest portion of the upper. Degrease the upper and the bolt carrier, so lube does not mask the problem. Slide in the bolt carrier and note where it begins to get tight. Lapping will not work in this case. Leave the whole upper assembled. Clamp the upper by the carry handle in a vise. Use strips of leather or rubber so that you do not mar the upper. Cut the leather from an old belt, tops of old boots, rubber from the tops of old rubber boots, etc. Do not clamp such that you will damage the rear sight assy. Prop up the muzzle end with an old paint can or something so that it will stay horizontal. What you will do now is GENTLY pry the sides apart, just a little at a time, until the bolt carrier slide smoothly. Use some large combination wrenches. 7/8" and 15/16" or 1", etc. Tape the open ends with electrical tape so the ends won't scratch the inside of the receiver. Place the wrenches with the open ends (taped) all the way down in the charging handle channel, and note where they will touch the sides of the upper rx. Wrap a few wraps of electrical tape there on the wrenches, too. Position one to bear against the tight spot even with the rear of the ejection port. Position the other in front of it, and gently pull the two wrenches apart, spreading the sides. Go just a little at a time, trying the bolt carrier often. You will feel inserting the carrier gets easier and easier, then suddenly free up all the way. You are done. Thank, you thank you, keep the applause down, you are embarrassing me. 
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