DrawandDuck Posted December 13, 2007 Share Posted December 13, 2007 Ok need some input on what the problem could be. I've had an 18" upper that I haven't used much but I am setting up an open upper and a tactical upper. The 1st round feeds, fires and extracts fine but the bolt will not close 100% on the next round. I have searched on head spacing with little luck. With the bolt completly closed on a round it is damn near impossible to get the bolt back, like it is stuck in chamber, had to use a 4x4 post to hit latch on to get bolt to open. I have shot this upper numerous times but it has been almost 2 years ago. I cleaned and lubed the upper but it does not help. ANY THOUGHTS?? Thanks in advance Randal Link to comment Share on other sites More sharing options...
GentlemanJim Posted December 13, 2007 Share Posted December 13, 2007 Are you using factory ammo or reloads....sounds like improper headspace crud in the lugs of the barrel extention...dirty chamber...dirt in bolt carrier(gas piston or rings) ammo TOO long Jim Link to comment Share on other sites More sharing options...
3gunner Posted December 13, 2007 Share Posted December 13, 2007 Ok need some input on what the problem could be. I've had an 18" upper that I haven't used much but I am setting up an open upper and a tactical upper. The 1st round feeds, fires and extracts fine but the bolt will not close 100% on the next round. I have searched on head spacing with little luck. With the bolt completly closed on a round it is damn near impossible to get the bolt back, like it is stuck in chamber, had to use a 4x4 post to hit latch on to get bolt to open. I have shot this upper numerous times but it has been almost 2 years ago. I cleaned and lubed the upper but it does not help. ANY THOUGHTS?? Thanks in advance Randal Hi Randal, Is the problem with hand loads or new ammo? What bbl is in it?It does sound like a Head space problem, how do the fired cases look? Lenard Link to comment Share on other sites More sharing options...
GentlemanJim Posted December 13, 2007 Share Posted December 13, 2007 Most AR15s use milspec parts ...and are almost interchangeable...but could you have swaped bolts?? If the rifle was operational at one point...something has to have changed. The case may not be going fully into the chamber..rust,damage or dirt. wear will cause excessive headspace(too loose) so thats not the issue. I wish I could drop a gauge in it. Jim Link to comment Share on other sites More sharing options...
DrawandDuck Posted December 13, 2007 Author Share Posted December 13, 2007 Reloads with new brass OAL is 2.235 (shoot fine in my 16" upper). Tried 2 different bolts JP ultralight and std Bushmaster. Bolt and receiver was clean. Verified no rust or crud in chamber. Its JUST ODD!!! Here are a few photos, don't think they will help, I do not have a gague but rounds are snug in chamber. It DID work previously but have been shooting 16" as that is all we need around here. Link to comment Share on other sites More sharing options...
GentlemanJim Posted December 13, 2007 Share Posted December 13, 2007 If you have tried different carrier and bolt assemblies...it has to be the chamber...barrel extention..or ammo related what is the length of your brass...and have you case gauged it? you may have a short chamber...it would shoot factory 223 but not 556 max length is 1.760 If your load is way HOT it may act the same way will it cleanly cycle shells not firing them??(carefull playing with live ammo to check!!!) Jim Link to comment Share on other sites More sharing options...
3gunner Posted December 13, 2007 Share Posted December 13, 2007 I still think it may be ammo. Try some new ammo and see how that works, save the fired cases. I have a RCBS case cage we can check your fired brass with your reloads. Let me know Link to comment Share on other sites More sharing options...
DrawandDuck Posted December 13, 2007 Author Share Posted December 13, 2007 (edited) If you have tried different carrier and bolt assemblies...it has to be the chamber...barrel extention..or ammo relatedwhat is the length of your brass...and have you case gauged it? you may have a short chamber...it would shoot factory 223 but not 556 max length is 1.760 If your load is way HOT it may act the same way will it cleanly cycle shells not firing them??(carefull playing with live ammo to check!!!) Jim Lenth of brass is 1.751. Ammo is .223, not HOT running avg. 2800 fps to make minor power factor. I would have to rule out the ammo as it has ran PERFECTLY in my other upper and 2 other of my buddies guns. YES IT IS DOING THE SAME THING NOT FIRING JUST CYCLING the rounds. Before putting in safe I ran approx 1500 rounds through it with no problems. The receiver was a Bushmaster Carbon 15 but I had a BRAND NEW BUSHMASTER forged receiver that I changed out last night and it does the SAME THING!! Everything works fine until you chamber a round so what else could it be but the barrel? Oh, I tried some federal and wolf (real brass) that I hand and it does NOT function either. If you let the bolt close slowly it will stop 1/4-1/2" from going into battery, now if you rack the round FAST it seats but is a bastard to get out, hammer handle required!! I do not have the patience of this, I might just order a new barrel as I feel it is the issue. Thanks for the input!! Leonard, If you are planning to be at the range the Thur/Fri prior to the Rifle match let me know as I will be there setting up that week and I will bring it with me. This is not my primary upper just one I wanted to get set up so I do not have to swap out optics going from open to tatical. Just took the spare receiver, a 14" iron sight barrel (have not had time to cut the iron sight off as I do not know how to use one of those) and factory handguards back on and it cycles FINE......What in the hell could have happened to that barrel????? Things like this drive me NUTS, there has to be a REASON!!!! Edited December 13, 2007 by DrawandDuck Link to comment Share on other sites More sharing options...
wsimpso1 Posted December 13, 2007 Share Posted December 13, 2007 Chambers do not get shorter with use. However, I have seen chambers that were a little short or tight, and they would sometimes not run well with different ammo, unsized new brass, and different bullets. Bottleneck cased guns are like this. Ammo that runs in one may be too big for another chamber, particularly if the chamber is a little tight. Is it a "Match" chamber? Some of those are tight. The Wylde reamer may open the chamber a bit and allow more ammo latitude. I could not tell by looking at your photos if the cartridges that stop things had any evidence of hard contact and or crud on anything. You have to look closely at the cases, and a magnifier helps: If the chamber shoulder has crud, it will show up as little marks (dents) or debris on the case shoulder while the case head will be burnished. Crud can develop over firing and time. Also, a quick wipe with Hoppes can cause copper deposited on the throat in firing to "bloom" (the copper is corroded by the ammonia in the solvent), so I would seriously suspect that the shoulder or throat area of the chamber is dirty. Really seriously. This is taken care of with solvent and a chamber brush, and then JB bore cleaner; If the headspace is too short for these rounds, it will show up as burnish marks over much of both the shoulder and case head. If the headspace on this rifle is a little tight, it can be fixed with a new barrel or by finding a 'smith who knows how to use a chamber reamer, but since it has run in the past, I would not suspect this; If the ejecter is bound, it will show up as burnish marks on most of the case shoulder but only on a segment of the case head. You further check this by trying to cycle the ejector with a fired case. You fix this with some solvent on the ejector and exercise it with a fired case, or by drifting out the retention pin, cleaning thoroughly and reinstalling the ejector and spring; If the bullet is interfereing with the throat, there will be marks on the bullet ogive, 1/8" or so forward of the case mouth. This can be due to several things - too short of a throat, copper crud and primer ash built up on the throat, or ammo loaded too long. Solutions are ream using a reamer with a longer throat, clean the barrel, seat bullets to a shorter length. I doubt the first one and the last one from what you said about other ammo and that it ran before. I do suspect that the throat is dirty. Clean the chamber and then the bore, first with a copper solvent and then with JB Bore Compound. Last comment - the M-16 style rifle has substantial mass in the carrier. When a round is stuck in one, the preferred method for opening the bolt is to "mortar clear". This sounds worse than it is. Hold the rifle with one hand on the forend, the other on the operating handle holding the latch open like you would to clear the piece. With the muzzle vertical, raise the gun and bring it down butt first on the ground or a table. Gently at first, and add more thump as necessary. Between pulling on the handle and the inertia of the carrier, it tends to come open pretty easily most of the time, and is far less abusive than thumping on the charging handle. Billski Link to comment Share on other sites More sharing options...
lynn jones Posted December 13, 2007 Share Posted December 13, 2007 check the gas system on the bolt. if the screws are loose, that can cause a lot of problems i had to stake mine again. lynn Link to comment Share on other sites More sharing options...
bigbrowndog Posted December 13, 2007 Share Posted December 13, 2007 also check to see if gas key on bolt carrier and gas tube lint up properly or do they drag against each other Trapr ` Link to comment Share on other sites More sharing options...
AustinT Posted December 17, 2007 Share Posted December 17, 2007 I've had the same problem using some bulk reloads I bought. I pocketed a couple of the rounds that got stuck in the chamber and checked the headspace using an RCBS precision mic...the headpace was 3 thousandths over max, and that was AFTER it got crammed in the chamber. The chamber on your rifle that's not working may be a little shorter than on your other rifle, hence the headspace issues. I'd get with 3gunner and let him gauge your rounds. Your resizing die probably needs to be screwed down a little more, not a big deal. Link to comment Share on other sites More sharing options...
mpeltier Posted December 19, 2007 Share Posted December 19, 2007 (edited) its the DUST------sorry, I couldn'y resist. From whats been posted I would suspect bolt/carrier first. have you changed gas rings and checked for smooth operation of the bolt? Clean and lube, then try factory ammo and it will probably work. Edited December 19, 2007 by mpeltier Link to comment Share on other sites More sharing options...
BillL223 Posted December 19, 2007 Share Posted December 19, 2007 This has been mentioned but I know that in my JP, I need to be sure my brass has been resized enough to go in their chamber check gage. Get one of theirs or equivalent, oal length of the case is not usually the issue. Also, I have found ARs , the way we use them, are very prone to building up copper in the throat. I have had the bullet actually pull out of the case when I unloaded. This makes a mess and obviously indicates problem. I regularly use copper solvent and occasional JB in the throat area to solve this problem. Link to comment Share on other sites More sharing options...
ap3 Posted December 19, 2007 Share Posted December 19, 2007 "I do not have a gauge but rounds are snug in chamber" A small investment for safety and reliability. JP chambers are tighter to the point that ammo that will fit in a standard case guage will be tight or not fit in a JP case gauge. This is why the ammo will run in your buddies rifle and not yours if the cases are not sized enough for the chamber. Link to comment Share on other sites More sharing options...
3gunner Posted December 20, 2007 Share Posted December 20, 2007 Brent and I will be out Friday to help with the rifle match. Will bring go no-go gages,rcbs case gage and whatever else we can think of. Bring some of your reloads and any fired cases from the upper you may have. see what we can find out. Link to comment Share on other sites More sharing options...
wsimpso1 Posted December 24, 2007 Share Posted December 24, 2007 Are we gonna hear what you guys found out? Come on with the scoop! ; ) Seriously, did you folks get it figured out? We have folks that want to learn from this... Billski Link to comment Share on other sites More sharing options...
DrawandDuck Posted December 24, 2007 Author Share Posted December 24, 2007 As this is a backup upper not had time to "fool" with it lately. Hopefully after Christmas I will have time to figure it out. I have broken everything down sitting on the bench. Leonard and Brent are speaking of this Friday. Randal Link to comment Share on other sites More sharing options...
00bullitt Posted December 24, 2007 Share Posted December 24, 2007 (edited) Search that barrel extension and upper receiver for a blown primer..........or even e piece of a blown primer like the anvil. I have had a primer anvil get stuck and flattened to the inside of the bolt lugs and wreak havoc on me exerting the same exact symptoms as you're dealing with. I finally found the piece after unbarreling the gun and removing the barrel extension. Try probing the inside of the barrel extension with a pick tool. Also search around the gas tube where it enters the upper. Search the entire upper and lower until you are satisfied there is not a foreign object in your gun. I am willing to bet that is you're problem considering the gun ran fine and now it does not. Oh yeah.....one other thing I forgot. If you painted your gun yellow like you do everything else ............it could just be that your rifle hates you now and needs debitchulation which I can handle for you next Saturday with a can of black krylon. Edited December 24, 2007 by 00bullitt Link to comment Share on other sites More sharing options...
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