survivalshop Posted July 22, 2017 Report Share Posted July 22, 2017 4 hours ago, 98Z5V said: SS, YOU are a prime candidate for a genuine Armalite AR-10 gas tube. Big time, brother. WAY bad. This 20" rifle has " 0 " issues from day one & its my first 308 Build , before I even knew about this Forum . As I said , I think many factors determine what works with which Gas Tube & this rifle is a prime example , I lost count on how many rounds have been through this rifle . I know I have some that are in the middle , but this reminds me of what Faxon Barrels said about their testing & changing of the Barrels Gas Port , just makes me think its just not all about Tube Length & not saying it won't help in some cases , but not all . About this Thread , the BCG not locking back can be a lot of things , but this rifle is functioning & having intermittent feeding issues , which could be the BCG not reciprocating far enough back to catch the base of the cartridge , it could be a gas system issue with short stroking , but i my experience if this was the case , the feeding issue would be more frequent , not just about every twenty rounds . The Barrels Gas Port should be sized , as I have already posted , the Spring is defiantly suspect & should be replaced ( Tubb's Flat wire Spring is a progressive type Spring & will smooth out any AR Action ) , the Gas Block has been checked three times , so we have to assume its not the issue . The Magazine brand change is easy & inexpensive to try , because if the Mag is not sitting high enough in the mag Well ( & we have seen a lot of this lately ) it will cause this same issue . Another thing or two can be checked , one is the Bolt Catch , is it for an 308AR & is not interfering with BCG Travel , os it resting deep enough in it cut in the Lower Receiver , also sometimes the Hammer interference can slow the BCG down , the back of the Hammer can hit the Disconnector & put pressure on the bottom of the Bolt Carrier. Try one thing at a time , to me the Buffer Spring would be first , then Magazine , then check the Barrels Gas Port size & we can compare with the info we have seen in the past & we have seen quite a few that were too small to operate the Action properly. Good luck , isn't this fun , I think its why the 308AR is a real build . Quote Link to comment Share on other sites More sharing options...
washguy Posted July 22, 2017 Report Share Posted July 22, 2017 (edited) Flabber So take your unloaded rifle and make the bolt catch...look into the side while its open and caught...where is the bolt catch holding the bcg? And then while its caught gently pull back and how much does the bcg move backwards off the catch till it bottoms out? Wash Edited July 22, 2017 by washguy Quote Link to comment Share on other sites More sharing options...
washguy Posted July 22, 2017 Report Share Posted July 22, 2017 (edited) Flabber look at this pic see how the catch is holding... This is the way it should look now from that hold of the bcg how much further can you pull back? if the spring doesn't solve the hold back issue its time to check your gas port....I know you're thinking no way a barrel mfg could put the wrong gas port on a barrel...lemme tell ya...they mostly don't have a clue as to what the rifle needs to cycle...sooo....I have all my rifles at the middy length...but this is where you should start looking and report back.....get you some numbered drill bits #42 .0935 #43 .0890 #44 .0860 #45 .0820 (most all of mine are .0820) #46 .0810 #47 .0785 lets see what ya got? when you buy the bits go ahead and get a wooden dowel rod that will fit in your barrel...ive got a feeling you're gonna be doing some drilling and the dowel will protect the barrels other side Wash Edited July 22, 2017 by washguy Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted July 23, 2017 Author Report Share Posted July 23, 2017 Wash - Yes my mags wobble back and forth when they are locked in. 15 hours ago, survivalshop said: Try one thing at a time , to me the Buffer Spring would be first , then Magazine , then check the Barrels Gas Port size & we can compare with the info we have seen in the past & we have seen quite a few that were too small to operate the Action properly. I think that's what I'll do is methodically work my way through each part of the gun to check and see exactly where the problem is starting with the buffer spring. Once the bolt is locked back I'm able to pull it back about 1/4" with the charging handle. See the pic. Quote Link to comment Share on other sites More sharing options...
washguy Posted July 23, 2017 Report Share Posted July 23, 2017 (edited) On 7/21/2017 at 10:36 AM, Flabbergasted said: The mag release button is threaded on by a few threads. It seems like it is too short for the width of my gun. Flabber you assembled this rifle? the mag release button is not installed correctly.......remove upper from lower......push in the mag release and unscrew the release completely...lets start over.....get you some blue painters tape or whatever tape and lay down tape on the lower so we don't scratch up the lower when we put the mag latch back on.......have you a punch, pencil, screwdriver handy....so put the latch back on with the mag release button....so now you got it on with a couple of threads....right? Now take the tool of choice and push on the mag button till it bottoms out while spinning down the release...you will keep spinning on the latch while you are pushing the mag button until the latch almost hits the lower...so now you remove the tape and the latch threads will be almost to the top of the mag button....now its on correctly....the mags still loose? wobble on the mags is no bueno Wash the position of bcg to the bolt catch is perfect...the 1/4 inch pull back good too ! you oil the bolt catch and does it move freely? im thinkin a new spring and a lancer or good ol metal mag will get ya going.....and a drill bit on standby say a #42 go big or go home Wash Edited July 23, 2017 by washguy Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 23, 2017 Report Share Posted July 23, 2017 ^^^ Good catch, wash. Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted July 23, 2017 Author Report Share Posted July 23, 2017 12 hours ago, washguy said: Flabber you assembled this rifle? the mag release button is not installed correctly.......remove upper from lower......push in the mag release and unscrew the release completely...lets start over.....get you some blue painters tape or whatever tape and lay down tape on the lower so we don't scratch up the lower when we put the mag latch back on.......have you a punch, pencil, screwdriver handy....so put the latch back on with the mag release button....so now you got it on with a couple of threads....right? Now take the tool of choice and push on the mag button till it bottoms out while spinning down the release...you will keep spinning on the latch while you are pushing the mag button until the latch almost hits the lower...so now you remove the tape and the latch threads will be almost to the top of the mag button....now its on correctly....the mags still loose? wobble on the mags is no bueno Wash the position of bcg to the bolt catch is perfect...the 1/4 inch pull back good too ! you oil the bolt catch and does it move freely? im thinkin a new spring and a lancer or good ol metal mag will get ya going.....and a drill bit on standby say a #42 go big or go home Wash The mag catch is is just too small. It was part of an Aero Precision M5 lower build kit. I had to screw it on so little in order for it to be able to use the mag release button without using a pencil every time to push the button in past the edge of the receiver. The threaded stem on the mag release is just too short. Aero even sells an extended button to remedy this problem I think they just need to make a different mag catch for the AR 308. I think I'm just going to ditch the mag catch and get the armalite one that was suggested. The threaded stem is longer. Quote Link to comment Share on other sites More sharing options...
washguy Posted July 23, 2017 Report Share Posted July 23, 2017 (edited) Here you go https://www.kakindustry.com/lr-308-parts/308-lower-parts/308-lpk-parts/special-extended-mag-release-arm longer .125 Wash Edited July 23, 2017 by washguy Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted July 23, 2017 Author Report Share Posted July 23, 2017 The bolt catch seems to move freely. When I insert an empty mag and pull the charging handle back the bolt catch holds the bolt. I know thats different from when the gun is being fired but it seems to move freely. I was reading a review for the Tubbs spring and the receiver said that they were having the same problem as me and they were using the same lower build kit. They said the Tubbs spring solved the issue. Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted July 23, 2017 Author Report Share Posted July 23, 2017 2 minutes ago, washguy said: Here you go https://www.kakindustry.com/lr-308-parts/308-lower-parts/308-lpk-parts/special-extended-mag-release-arm longer .125 Wash Thanks! Quote Link to comment Share on other sites More sharing options...
washguy Posted July 23, 2017 Report Share Posted July 23, 2017 3 minutes ago, Flabbergasted said: Thanks! https://www.kakindustry.com/lr-308-parts/308-lower-parts/308-lpk-parts/lr308-carbine-buffer-heavy might as well get you one of these...they are awesome.... to be used after we get it running to tune down recoil impulse . Wash Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 23, 2017 Report Share Posted July 23, 2017 (edited) 1 hour ago, Flabbergasted said: The mag catch is is just too small. No, it's not - you just need to thread it in more. You have to use something to push the button in, all the way, in order to thread the catch into the button more. Otherwise, the catch just hits the left side of the receiver, and you won't get it thread in far enough. When that happens, you don't have enough spring pressure on the catch to hold the magazine properly. It's harder to do once the bolt catch is installed - because then you have to clear that, too. I use a fat punch to push them in, and spin that mag catch more. AR15 mag catches work just fine in 308ARs. You just don't thread them all the way into the button like an AR15 - because the receiver is wider on a 308AR. Edited July 23, 2017 by 98Z5V Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 23, 2017 Report Share Posted July 23, 2017 Flab, here you go. All these things run generic AR15 mag catches. First pic is the .338 Fed - depth of the mag catch threaded shaft to the top of the button is 0.168". Second pic it the 16" .308AR, depth is 0.145" - so there's a half turn difference between those two large frame ARs, right there. Third pic is the 25-45 Sharps, which is just AR15 receivers - flush. Check your depth. It needs to be somewhere between those two numbers I listed - 0.168"~0.145" deep, shaft end to button top. Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted July 24, 2017 Author Report Share Posted July 24, 2017 9 hours ago, 98Z5V said: Flab, here you go. All these things run generic AR15 mag catches. First pic is the .338 Fed - depth of the mag catch threaded shaft to the top of the button is 0.168". Second pic it the 16" .308AR, depth is 0.145" - so there's a half turn difference between those two large frame ARs, right there. Third pic is the 25-45 Sharps, which is just AR15 receivers - flush. Check your depth. It needs to be somewhere between those two numbers I listed - 0.168"~0.145" deep, shaft end to button top. When I installed the mag catch I used a pencil to push the mag release button in past the receiver and proceeded to tighten it so the post sits almost flush with the button, like on an AR 15. I soon realized that that would not work on an AR 308. So I in screwed the mag catch until it was tight enough to hold the mag but not too tight to where I would have to push the button in past the receiver to get the mag to drop out. Just enough so I could drop mag by pressing the button as far in as I could with my finger. The release button looks like yours in the first pic. I haven't measured it yet but it looks the same as yours. I even loosened and tightened it a couple of times to make sure it was tightened the right amount. When the magazine is locked in I can move it back and forth with my hand, but just moving the gun around without touching the mag it does not move. Is this how tight the mag should be? I have nothing to compare this to since this is my first At 308 build. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 24, 2017 Report Share Posted July 24, 2017 I also use a Pencil with an eraser & unsharpened , the Mag Release adj. should be felt the same as an AR 15 , no different , just that an AR 15 Catch button in a 308AR is threaded on less . It should function the same as a AR 15 , with free drop & enough to hold the Mag in place . Most 308AR Lower Receivers may be different in how much this adj. is . Its why I like the Armalite AR 10 Catch , the one posted by Washguy from KAK , I would have to look at the Pad & compare it to the Armalite catch pad , but its nice to have the extra long stem , thats for sure . Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 24, 2017 Report Share Posted July 24, 2017 I found this looking for something else http://www.scopelist.com/Armalite-AR-10-A-Lower-Parts-Kit.aspx , there are parts you don't need , but you can probably make your $$ back by selling the rest of the kit to one of the few AR 10 owners here maybe even mark it up to get all your $$ back . I couldn't resist Quote Link to comment Share on other sites More sharing options...
DNP Posted July 26, 2017 Report Share Posted July 26, 2017 On July 23, 2017 at 10:10 AM, 98Z5V said: ^^^ Good catch, wash. Ba dump bump! Quote Link to comment Share on other sites More sharing options...
Rsquared Posted July 26, 2017 Report Share Posted July 26, 2017 On 7/24/2017 at 7:39 AM, survivalshop said: I found this looking for something else http://www.scopelist.com/Armalite-AR-10-A-Lower-Parts-Kit.aspx , there are parts you don't need , but you can probably make your $$ back by selling the rest of the kit to one of the few AR 10 owners here maybe even mark it up to get all your $$ back . I couldn't resist Smart ass! Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 26, 2017 Report Share Posted July 26, 2017 2 hours ago, Rsquared said: Smart ass! Thank you ! Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted August 25, 2017 Author Report Share Posted August 25, 2017 I finally got around to addressing the issue that I was having with my gun. I wanted to try one possible fix at a time to pin point exactly what the problem was so I purchased a Tubbs buffer spring from LaRue Tactical, since it was recommended to buy there since they have the best price. Once I installed it I noticed a significant reduction in the spring tension when I cycling the bolt. The previous buffer spring was part of an Aero Precison M5 lower build kit and to me the buffer spring felt really stiff, but since this is my first 308 build I had nothing to compare the buffer spring to. I did however read a review someone wrote who was having the same issue as I was when they used Aero's buffer spring. They said once they switched to the Tubbs the problem went away. I took the gun out to the desert yesterday with a buddy of mine and shot 40 rounds of some cheap Monarch 150 gr ammo. I used the same magazines as I did when I had FTF and failure to lock the bolt back on the last shot. All 40 rounds cycled perfectly! No FTF and the bolt locked on the empty mag every time. I'm guessing the buffer Aero Precision spring was stiffer and may have been better suited for a gun with more gas. I'm just glad it was as simple as swapping buffer springs. Quote Link to comment Share on other sites More sharing options...
Flabbergasted Posted August 25, 2017 Author Report Share Posted August 25, 2017 Here's a pic of the gun, just in case you wanted to see it. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted August 25, 2017 Report Share Posted August 25, 2017 Nice rifle! I swapped an Aero spring for a Tubb's in my Matrix build, no issue just wanted to try it. I felt the same results which puzzled me as the Tubb's was supposed to be a heavier rated spring, figured it must have something to do with points at which the spring exerts the pressure. Either way I like them. Quote Link to comment Share on other sites More sharing options...
washguy Posted August 25, 2017 Report Share Posted August 25, 2017 2 hours ago, Flabbergasted said: I finally got around to addressing the issue that I was having with my gun. I wanted to try one possible fix at a time to pin point exactly what the problem was so I purchased a Tubbs buffer spring from LaRue Tactical, since it was recommended to buy there since they have the best price. Once I installed it I noticed a significant reduction in the spring tension when I cycling the bolt. The previous buffer spring was part of an Aero Precison M5 lower build kit and to me the buffer spring felt really stiff, but since this is my first 308 build I had nothing to compare the buffer spring to. I did however read a review someone wrote who was having the same issue as I was when they used Aero's buffer spring. They said once they switched to the Tubbs the problem went away. I took the gun out to the desert yesterday with a buddy of mine and shot 40 rounds of some cheap Monarch 150 gr ammo. I used the same magazines as I did when I had FTF and failure to lock the bolt back on the last shot. All 40 rounds cycled perfectly! No FTF and the bolt locked on the empty mag every time. I'm guessing the buffer Aero Precision spring was stiffer and may have been better suited for a gun with more gas. I'm just glad it was as simple as swapping buffer springs. Flabber ive been a tubs fan forever but I tried this combo a month ago and its the best yet.....a sprinco orange spring and a KAK car308 heavy buffer like slashes but half the price......less felt recoil and a very strong round strip action back to battery....try an ornage first and then the 55 bill buffer if you wish Wash Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted August 25, 2017 Report Share Posted August 25, 2017 6 minutes ago, washguy said: Flabber ive been a tubs fan forever but I tried this combo a month ago and its the best yet.....a sprinco orange spring and a KAK car308 heavy buffer like slashes but half the price......less felt recoil and a very strong round strip action back to battery....try an ornage first and then the 55 bill buffer if you wish Wash Did you notice much difference in the effort required to pull the charging handle with that orange spring? Quote Link to comment Share on other sites More sharing options...
washguy Posted August 25, 2017 Report Share Posted August 25, 2017 3 minutes ago, jtallen83 said: Did you notice much difference in the effort required to pull the charging handle with that orange spring? Yeah I have to use my toes to help pull it back but you can be sure that the orange spring strips the round and gets into battery pronto fast Wash Quote Link to comment Share on other sites More sharing options...
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