BlazenT45 Posted April 18, 2016 Report Share Posted April 18, 2016 I finished my Matrix build 6 months ago and just finally took it out to the range Saturday. first 20 rounds failed to pick up the second round so I would imagine it was short stroking. then I lubed it up really good, for the next five or six rounds it's fed fine but after that it started picking up two rounds at a time. Has anyone experienced this problem before any helpful hints would be much appreciated. Quote Link to comment Share on other sites More sharing options...
blue109 Posted April 18, 2016 Report Share Posted April 18, 2016 Gonna need a little more info than receiver manufacturer to be any help. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 18, 2016 Author Report Share Posted April 18, 2016 Yes you will sorry about that had a phone call come in right in the middle of writing the topic. Okay my build is a hodgepodge of various manufacturers. Matrix Aerospace upper and lower combo and handguard. 18 inch Mega 308 Barrel mid-length gas. Red Barn Armory bolt carrier group and Red Barn Armory AR-15 mid-length gas tube and .750 gas block non-adjustable have no idea what diameter gas ports are. AR 10 B ArmaLite upper and lower parts kit. With a modified bolt catch Magpul ubr stock and receiver extension. and the JP Enterprises silent captured spring AR-10 version. Magpul pmags used two of them had the same problem. I was shooting the cheap ZQI Walmart ammunition. again any help or advice would be appreciated. Quote Link to comment Share on other sites More sharing options...
blue109 Posted April 18, 2016 Report Share Posted April 18, 2016 First thing I would try before I change anything is some better ammo. I've been seeing people complain about the newer ZQI ammo, Both here and on other forums. I think they may have lost a little quality. Probably directly related to demand. Buy a box of good stuff like FGGM and just bang through it so you can eliminate that variable. Just load one round to start with and see if it locks back. Do that a few times to eliminate gas system problems. If you are locking back you should be ok. Component wise, the UBR/JP setup stands out as something to look at, but I'd check the above before I messed with it. Quote Link to comment Share on other sites More sharing options...
beantown Posted April 18, 2016 Report Share Posted April 18, 2016 13 minutes ago, BlazenT45 said: (snip) Matrix Aerospace upper and lower combo and handguard. 18 inch Mega 308 Barrel mid-length gas. Red Barn Armory bolt carrier group and Red Barn Armory AR-15 mid-length gas tube and .750 gas block non-adjustable have no idea what diameter gas ports are. AR 10 B ArmaLite upper and lower parts kit. With a modified bolt catch Magpul ubr stock and receiver extension. and the JP Enterprises silent captured spring AR-10 version. Magpul pmags used two of them had the same problem. What did you modify? I only ask this for my own knowledge base. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 18, 2016 Author Report Share Posted April 18, 2016 (edited) I Dremeled the bolt catch just enough to clear the upper receiver, during the test fit it was hitting the upper receiver. Had no problems with the modification during range day. Edited April 18, 2016 by BlazenT45 Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 18, 2016 Author Report Share Posted April 18, 2016 Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 Thanks blue, better ammunition was the next step for accuracy testing. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted April 19, 2016 Report Share Posted April 19, 2016 I'd try a steel mag and see if you have the same problem. Survivalshop has a rifle that won't use PMAGs, but works fine with steel mags. Remember, don't leave pmags loaded without the covers clipped on. The upward pressure on the polymer lips can weaken them overy time. The covers take the pressure off the lips by pushing down slightly on the top round. I keep all my pmags loaded, but I also keep the covers on. I can't imagine it being anything other than an ammo or mag problem. I've never had a rifle try to strip two rounds at a time and can't think of how one could do that, unintentionally or not. Keep her wet. Chances are, once the gas system gets seasoned, things may start working out properly. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 Now the question is, are there steel Sr 25 magazines available that will work with the Matrix receivers? Quote Link to comment Share on other sites More sharing options...
blue109 Posted April 19, 2016 Report Share Posted April 19, 2016 My DPMS mag fits nice, but didn't get a chance to try it out. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 Good to know, I was just inspecting the BCG and it seems like the gas key bolts are loose and not properly staked I'm wondering if that may be an issue. Does anybody know what the torque spec is on the gas key Bolts? Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted April 19, 2016 Report Share Posted April 19, 2016 Google search gave me results from 40-55 inch/lbs. Armalite was on the high end with 55 inch/Lbs. Quote Link to comment Share on other sites More sharing options...
CrashOverRide.308 Posted April 19, 2016 Report Share Posted April 19, 2016 Hmmm... Im having issues with my bcg picking up a round when bcg is release off of bolt catch. Maybe I should try steel mag instead of pmags. But before hand nothing in my rifle is lube though. So I'll start with that. Also built with matrix aerospace. Havent shot mines either. Hoping this weekend. Good luck Blaze. Will keep checking up on your thread. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 1 hour ago, jtallen83 said: Google search gave me results from 40-55 inch/lbs. Armalite was on the high end with 55 inch/Lbs. Thanks jtallen I didn't even think about doing a Google search last night, I must a had a senior moment. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 1 hour ago, CrashOverRide.308 said: Hmmm... Im having issues with my bcg picking up a round when bcg is release off of bolt catch. Maybe I should try steel mag instead of pmags. But before hand nothing in my rifle is lube though. So I'll start with that. Hey mine was doing that too! I removed the pmag and I release the bolt catch and problem was solved didn't pickup a round......lol But seriously a very nice gentleman at the range let me borrow his Lube then I soak the bastard and still had issues. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted April 19, 2016 Report Share Posted April 19, 2016 12 hours ago, BlazenT45 said: I finished my Matrix build 6 months ago and just finally took it out to the range Saturday. first 20 rounds failed to pick up the second round so I would imagine it was short stroking. then I lubed it up really good, for the next five or six rounds it's fed fine but after that it started picking up two rounds at a time. Has anyone experienced this problem before any helpful hints would be much appreciated. I do have a early CMMG lower that will not function reliably with the first Gen.LR PMags , but the Gen. 3 work fine. My measurements show the Gen. 3's sit higher in the mag well , they changed where the Mag Catch notch is on the Mag Body , I have a Thread on it around here some where. Sounds like a Cartridge is popping out from under the feed lips of the mag as the BCG is stripping a fresh round from the Mag. or the Bolt & the edge or the Bolt Carrier is stripping rounds from the mag at the same time . UBR with a AR 10 length JP's SCS , not sure if the Receiver Extension ( buffer tube ) with the UBR is compatible with AR 10 components , I'm not that familiar with that stock, might be a fitment problem. Others may know. Quote Link to comment Share on other sites More sharing options...
blue109 Posted April 19, 2016 Report Share Posted April 19, 2016 (edited) I know guys have had good luck with the UBR and slash heavy buffer set up, but I'm not sure about that JP. Edited April 19, 2016 by blue109 Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 19, 2016 Author Report Share Posted April 19, 2016 (edited) I am able to pull the bolt all the way back until it locks so I don't think it would be that receiver extension or the JP silent captured spring as an issue. Edited April 19, 2016 by BlazenT45 Quote Link to comment Share on other sites More sharing options...
survivalshop Posted April 20, 2016 Report Share Posted April 20, 2016 (edited) It could be several things , but manually charging the action & a fired round doing it are not the same . ( 1 )Try one round in the mag & fire the one round & see if the Bolt is held back on last round ( this tells you a lot about the function of the Action ).Then put two in , test fire & then three rounds , If there are issues , they should show up & take a photo of the malfunction , if you can safely . ( 2 ) if it hasn't been mentioned you , run the BCG wet , wet . ( 3 ) You will need to make sure your Gas Block is where it should be , blowing down the barrel is not a fool prof way of knowing if its correctly orientated .I don't remember any issues with a Mega Barrel , as far as Gas Port size , but we have had a few other brands that have short changed the 308's gas delivery capabilities . Still it would not hurt to know the Port size . ( 4 ) I have no experience with the Red Barn stuff , so your on you own as being the tester of their BCG . Glad you used a Receiver set from the same manufacturer , eliminates a lot of potential issues . You have a build with multiple manufacturers components , some may be proprietary , so may take some fitment & in some cases a different manufacturers replacement component , to get the action to work reliably . Sounds like another 308AR build to me .? Edited April 20, 2016 by survivalshop Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 20, 2016 Author Report Share Posted April 20, 2016 Looks like I have a lot of things to try on my next range trip. I've been using the spray REM oil, does anybody have any better suggestions? (1) retorque the gas key on BCG (2) check to see if the gas block is aligned correctly and measure gas port (3) different ammo (4) run it wet wet and yet even wetter (5) test if Bolt locks back when firing single-round What about lubing the JP silent captured spring? Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 20, 2016 Author Report Share Posted April 20, 2016 Quote Link to comment Share on other sites More sharing options...
unforgiven Posted April 20, 2016 Report Share Posted April 20, 2016 Looks like you got the bases covered brother.Lube on the buffer assembly couldn't hurt.Check gas block for thightness. Quote Link to comment Share on other sites More sharing options...
BlazenT45 Posted April 20, 2016 Author Report Share Posted April 20, 2016 Thanks gentleman I will update this thread after my next range trip. Quote Link to comment Share on other sites More sharing options...
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