lonestartroy Posted February 21, 2017 Report Share Posted February 21, 2017 Have a newly built AR10 and having a constant problem. Usually when the gun is cold I can shoot 2-5 rounds and the gun fires and the primers have a good dent in them. Then once the gun has warmed up it fails to fire and the primers have light dents in them. Once I get the light dents I rack another round and sometimes it fires but most of the time it does not. I have cleaned everything and run it wet and still get the same results. The bolt appears to be fully seating. I have verified that the hammer spring is on correctly and have the correct buffer spring and buffer. I have no idea what is going on and could not find a post where someone was having the same issue. Please help. Thanks Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted February 21, 2017 Report Share Posted February 21, 2017 Welcome from Arizona! Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 Thanks. Quote Link to comment Share on other sites More sharing options...
blue109 Posted February 21, 2017 Report Share Posted February 21, 2017 What ammo? What trigger? Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 21, 2017 Report Share Posted February 21, 2017 You say AR 10 , is it Armalite components ? Or is it a DPMS pattern ? Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 I have used all factory ammo, Winchester, Federal, and one other that I can't remember now. The trigger is a two stage and think it is a rock river. I did not build the gun. It has a Matrix Aerospace upper and lower, 20" Hart barrel 308 win., JP buffer spring, and correct buffer. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 21, 2017 Report Share Posted February 21, 2017 1 hour ago, lonestartroy said: Usually when the gun is cold I can shoot 2-5 rounds and the gun fires and the primers have a good dent in them. Then once the gun has warmed up it fails to fire and the primers have light dents in them. Sounds like a tight chamber. If it's not - NOT - an Armalite, then it's NOT an AR-10. Not OUR call, that's ARMALITE's call. Get that straight, and it's NOT on us. Start a tech thread in the appropriate section on this... Welcome. Quote Link to comment Share on other sites More sharing options...
AnOldBiker Posted February 21, 2017 Report Share Posted February 21, 2017 Welcome to the forum Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 Have no idea what 98Z5V is talking about. Can someone please expand on this? Quote Link to comment Share on other sites More sharing options...
blue109 Posted February 21, 2017 Report Share Posted February 21, 2017 (edited) Only the Armalite AR10 is an AR10. It's a specific rifle model, not a generic label for all 308 cal AR style rifles. It may seem nit-picky but it causes issues since many people and even vendors and manufacturers sometimes say parts are "AR10" when they are not actually compatible with an AR10. Far as your issue...I have no idea why the first few shots work and noting after that. I've had issues with light primer strikes due to light triggers designed for AR15s but if it consistently acts the way you describe I have no idea. Either the shell is moving forward out of reach of the firing pin (unlikely) or the hammer is getting weaker or after the first few shots. To be clear Does it always act as you describe? Do you always get a few good ignitions and then always light strikes after that? or is it an occasional issue and sometimes it runs fine for a whole mag? Edited February 21, 2017 by blue109 Quote Link to comment Share on other sites More sharing options...
shepp Posted February 21, 2017 Report Share Posted February 21, 2017 4 minutes ago, blue109 said: Only the Armalite AR10 is an AR10. It's a specific rifle model, not a generic label for all 308 cal AR style rifles. It may seem nit-picky but it causes issues since many people and even vendors and manufacturers sometimes say parts are "AR10" when they are not actually compatible with an AR10. Far as your issue...I have no idea why the first few shots work and noting after that. I've had issues with light primer strikes due to light triggers designed for AR15s but if it consistently acts the way you describe I have no idea. I was thinking maybe the trigger wasn't resetting, cuz that's what my elftmen trigger was doing. It would fire one round light strike, I would eject that round via the charging handle then it would shoot a round and repeat. But idt I was ever able to shoot 4/5 rounds in a row Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 21, 2017 Report Share Posted February 21, 2017 Its as said by Blue109 , the 308AR rifles are in a couple of categories because of components , some are proprietary for the specific brand , Armalite AR10 , DPMS LR , which is the most prevalent of all the 308AR platforms , in both parts availability because of all the manufacturers that make components for this type and the last platform is also a DPMS system & its the their GII 308AR , smaller frame 308AR , with quite a few proprietary components . This is why we like to separate the different platforms because of the mixing of one platform with another can cause issues . You say a JP buffer , would it be their Silent Captured spring system ? Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 Blue109 yes it always acts this way. When I first shoot it get anywhere from 2-5 rounds then click and light strike. The 2-5 rounds that work have good dents in the primer. I pull the charging handle Loading a new round and it may or may not fire. Usually not. So it does not say Armalite anywhere. What should I call it? 308AR? This is Buffer spring: JP Tuned and Polished Extra Power Large Frame Carbine Buffer Spring SKU: JPS-OSC.308 Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted February 21, 2017 Report Share Posted February 21, 2017 11 minutes ago, lonestartroy said: BSo it does not say Armalite anywhere. What should I call it? 308AR? Usually going by the manufacturer and model listed on the receiver will get you by, but 308 AR or "large frame AR" are both recognized generic terms. Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 One more question. Which forum should I post this to? Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 21, 2017 Report Share Posted February 21, 2017 You can call her a 308AR or a Matrix 308AR , something to that effect , gives people a good idea of what they are dealing with . What Gas Block are you running . Some new builds may have issues when warmed up , depends on a few reasons , -type of lubricant used or not enough in the right places . -types of ( if any ) Coatings on BCG - Tight or Rough Chamber ( as has been mentioned ) - Gas signature issues ( Gas Block alignment , an adj. Gas Block not adj. correctly for break in , even the Barrels Gas Port not sized correctly ) First thing to do is start with one round in the Mag , chamber the round , fire the round & see if it locks back the BCG with the last round in the mag . Do that test & it tells us it not under gassed . We here , can go from there . The mods can move this to the Matrix or 308 Build section if you want . Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted February 21, 2017 Report Share Posted February 21, 2017 Moved to correct section. Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 I will try the one round thing and report back. Thanks. Quote Link to comment Share on other sites More sharing options...
shepp Posted February 21, 2017 Report Share Posted February 21, 2017 11 minutes ago, lonestartroy said: I will try the one round thing and report back. Thanks. Also try getting pictures of its failures Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 Survival shop Not sure what name brand the gas block is but it is adjustable. The screws that lock it down are on the bottom and the adjustment screw is on the right side if your looking down the barrel. It is under the hand guard and do not see any markings. I believe the BCG is a Aero Precision .308 BCG Nickel Boron APRH100185. The chamber appears smooth and if I drop a round in goes in and comes out easy. I have scrubbed it several times with a bore brush. I'm using break free gun oil. I took an AR class to learn how to properly break it down and lube everything and believe I have done that correctly. After the first time I shot it I cleaned the bolt and it is soaking wet in oil now. The BCG appears to function correctly and lock up tight even when closed slowly. Does not stick. When it does fire the spent rounds come out at 1 o'clock and about 6 feet or more away. If the chamber is tight does that mean it will need to be reamed out? Quote Link to comment Share on other sites More sharing options...
CrashOverRide.308 Posted February 21, 2017 Report Share Posted February 21, 2017 Someone correct me if I am wrong. But the spent round should be ejecting at 3 o'clock. As I myself have a Matrix w/ an OdinWorks adj. Gas block. Quote Link to comment Share on other sites More sharing options...
blue109 Posted February 21, 2017 Report Share Posted February 21, 2017 (edited) Head scratcher for sure. Probably outside my troubleshooting abilities, and without putting hands on the gun id be looking at trigger, chamber and BCG. the hammer could be losing energy due to a bent/broken spring, bad hammer pin, maybe not fully resetting. Make sure the firing pin isn't being obstructed and is sliding easy. Make sure the bolt is turning. I'd be worried the bolt might not be locking fully into the extension which would cause the pin to not protrude far enough into the chamber to pop the primer. That could certainly be caused by a tight chamber. Has headspace been checked on this gun? Edited February 21, 2017 by blue109 Quote Link to comment Share on other sites More sharing options...
lonestartroy Posted February 21, 2017 Author Report Share Posted February 21, 2017 I have not had the head space checked. Will a trigger and hammer out of an AR15 work in this gun. If so I could swap it out and try it. I have had several people that were in the military look at the gun and two have said that the hammer did not look like it had that much mass. The bolt passes the sling test, extends out fully when you flick it. Even got pipe cleaners to make sure the firing pin channel inside the bolt was clean and it was. The firing pin has a very minute amount of resistance in the last 1/4" of travel through the bolt. I can barely touch it and it falls through. If you drop the pin with the bolt facing down sometimes it does not bottom out. Cannot believe a proper working hammer would not make it work correctly. Again very light tough and it falls. Quote Link to comment Share on other sites More sharing options...
MikedaddyH Posted February 21, 2017 Report Share Posted February 21, 2017 Welcome from AZ ! Late to this one. 1st :Most people call this an ÀR-10 but we call it a AR-308 Quote Link to comment Share on other sites More sharing options...
MikedaddyH Posted February 22, 2017 Report Share Posted February 22, 2017 (edited) Check chamber, maybe rough as stated. Next take apart bcg and fire control group and look for a piece of metal then clean and lube each assembly. After that check gas block. Good Luck. Post some pics. Edited February 22, 2017 by MikedaddyH Quote Link to comment Share on other sites More sharing options...
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