D.R.D. Posted July 25, 2018 Report Share Posted July 25, 2018 Bolt is not locking back. Following rounds are not being chambered Running Federal 168gr Gold Medal Match Ammo I began opening up the adjustable gas block incrementally. No change. Could this be a mag issue? I'm running PMAGs - feeding lips? How do I know? Could this be a bolt or mag catch issue? I'm using Fulton Armory LPK. Again how would I know? I had the bolt carrier, (D. Wilson Mfg) and the buffer/spring (Armalite) permanently dry lubed with slipstream, and put wet slipstream on top of that. The gun shoots like a laser, but just won't cycle. Only 25 rounds total, through it at this point (shoots sub 3/4" MOA :) What order should I consider the above? Other issues I'm over-looking? Thanks, DRD Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 #1. Run it WET, if it isn't. #2. Way low round count, might need to shoot more to seal the gas system (gas block to gas tube, gas bloc to barrel). #3. Wide Open that gas block, right away. Always. Run it wide open, and cut it back from there, no matter what the manufacturer told you. #4. Highly doubt it's a mag issue, or a LPK issue, based on the reputation of both those manufacturers. Lube, and wide open gas block - gotta start there. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 " I had the bolt carrier, (D. Wilson Mfg) and the buffer/spring (Armalite) permanently dry lubed with slipstream, and put wet slipstream on top of that. " What receiver extension? Armalite parts for buffer/spring are the H3 buffer and the EA1095 spring? Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 (edited) Yes, the Armalite H3 buffer and the EA1095 spring in a UTG PRO tube: https://www.opticsplanet.com/leapers-utg-pro-6-position-mil-spec-extension-tube-for-308.html (Leaper's - I know, but the PRO series is made in the USA) Edited July 25, 2018 by D.R.D. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 1 minute ago, D.R.D. said: Yes, the Armalite H3 buffer and the EA1095 spring in a UTG PRO tube: https://www.opticsplanet.com/leapers-utg-pro-6-position-mil-spec-extension-tube-for-308.html THAT is the issue, man. Right there. Measure the internal depth, and you'll see it's 7.000". You need a tube that 7 5/8" with that recoil system. Armalite AR-10 Carbine Receiver Extension, or VLTOR A5 Receiver extension. Nothing else will be right. Can you even lock that bolt back? Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 (edited) It is 7 5/8" I researched before I purchased it, then measured it. It was made specifically for .308. Yes, the bolt locks back, no problem. Edited July 25, 2018 by D.R.D. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 You measured that to verify, yes? It's really 7 5/8" internal depth? I guess if you can lock it back by hand, then it is, 'cause that wouldn't happen on a 7" extension. Gas and lube, then. Shoot it more - needs more than 25 rounds, and needs lube. Got a build thread on this beast somewhere, listing the build details? Upper, lower, barrel, etc., by brand? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 (edited) Man, you're gonna have to stick a tape measure down this thing to show me - I've searched high and low, and I can't find any reference to the internal length of this receiver extension. I just can't. There are several sites saying that it's for the "AR-10" but we know how that is. Gotta stick that tape measure in it and put the pic up... I'm just sayin'... Edited July 25, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 Upper: · SI-Defense Billet .308 Upper Receiver · SI-Defense upper parts (port cover, spring, forward assist) · MI SS Gen II FF DPMS High .210 15” Handguard · 18” Lothar Walther Vartac 1:10 Barrel LW50 .750 Rifle-Length 6 groove 47oz. w/ matched NiB Bolt · Brake: Nathan Wright’s Muzzle-Brakes-and-More 3-port Beast · Mega Arms Slide Lock Charging Handle · D. Wilson Mfg Nitride Carrier (w/o Bolt) · Radical Firearms Adjustable Gas Block (.750) · Strike Industries Rifle-Length Gas tube Lower: · SI-Defense Billet .308 Lower Receiver · Lower parts kit w/o tcg Fulton Armory · Geissele SD-E Trigger · Grip: Ergo · Armaspec ST45 - 45 Degree Short Throw Ambi Safety Selector Switch · Stock: MOE with LaRue RISR and Magpul .70” buttpad extender · Leapers-UTG 6-Position Carbine Receiver Extension Tube · Armalite EC0120 AR10 Carbine H3 Buffer 5.4 oz. · Armalite EA1095 Spring · Magpul 7.62 P-Mag 8 lbs 14oz unloaded Optics: Burris XTR II 4-20x50 H59A1 Reticle Vortex Bubble Level ADM Recon-S 20 MOA QD Mount Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 I'll call leapers tomorrow, then take the buffer out and measure it Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 (edited) 12 minutes ago, 98Z5V said: Man, you're gonna have to stick a tape measure down this thing to show me - I've searched high and low, and I can't find any reference to the internal length of this receiver extension. I just can't. There are several sites saying that it's for the "AR-10" but we know how that is. Gotta stick that tape measure in it and put the pic up... I'm just sayin'... Hit this one, if you will, please - just saw your post. It's easy, just do it now, and no need tocall them for anything, man. Also, if you can, get a pic up of how far that gas tube protrudes into the upper receiver - need to see the relation of how long it is, and how far it goes into the cam pin cutout in the upper... That's an important factor... Edited July 25, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 How far should it go? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 How far should what go? The gas tube? Just get the pic. It should go to the very center of the cam pin cutout. If you're talking about the tape measure, into the receiver extension, it should go 7 5/8" into the receiver extension, measured at the top part of the receiver extension. Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted July 25, 2018 Report Share Posted July 25, 2018 Lothar Walther barrel, that's the problem... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 I was waiting for that... Wait, I wonder how long he had to WAIT for that?... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 25, 2018 Report Share Posted July 25, 2018 29 minutes ago, D.R.D. said: Upper: · SI-Defense Billet .308 Upper Receiver · SI-Defense upper parts (port cover, spring, forward assist) · MI SS Gen II FF DPMS High .210 15” Handguard · 18” Lothar Walther Vartac 1:10 Barrel LW50 .750 Rifle-Length 6 groove 47oz. w/ matched NiB Bolt · Brake: Nathan Wright’s Muzzle-Brakes-and-More 3-port Beast · Mega Arms Slide Lock Charging Handle SNIP... Is this a completely different build than the one gun described 3 months ago?... I'm just trying to figure shiit out here... Aaaaaaah, Floydie. Master Gunsmith of Everything... I miss that guy... Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 25, 2018 Author Report Share Posted July 25, 2018 (edited) Yeah, that wasn't my build, just a thread I responded to, I believe. It was a build idea, not my actual rifle. Matt, LOL - yeah, that damn LW. I only had to speak with them once, it was delivered on time, and shot less that a 3/4" group with the first 4 shots out of the tube. I should probably replace it.... ;-) 98ZV5 - I'll measure as soon as I can, then lube it silly, and try again with 3 different mags and let you know... Edited July 25, 2018 by D.R.D. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 26, 2018 Report Share Posted July 26, 2018 I'm pretty sure Lothar Walther Barrels use Armalite AR 10 Gas Port locations , which would be longer then used in AR 15/DPMS LR 308 . Though most 308 Barrels with Carbine gas positions , can run fine with a short protruding Gas Tube , Rifle length can be a bit picky , saying that I have a early 20" HB Krieger Criterion barrel from Fulton Armory that has shorter protrusion then is shown in this photo , its still far enough that its never been an issue . Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 26, 2018 Author Report Share Posted July 26, 2018 So, for best results with a rifle length gas system, how far should it protrude compared to the photo above? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 26, 2018 Report Share Posted July 26, 2018 (edited) The photo above is perfect. Right in the middle of the cam pin cutout, just like it should be. It's either gonna be that, or it's 3/16" too short. I looked all over Leapers UTG website, and they don't have a specific .308AR receiver extension. I could only find one receiver extension from them, and it's for the AR15. That's not gonna be the right receiver extension for using the Armalite AR-10 carbine recoil components... These are the two best sources of info on it that I could find: https://www.thefirearmblog.com/blog/2015/03/16/leapers-introduces-6-position-308-ar-receiver-extension/ In this one, straight from Leapers, when you look at all the "related items" in that long list, there is no 308-specific receiver extension... https://leapers.com/index.php?act=prod_detail&status=utg&itemno=TLU001D I'd bet that you have a receiver extension that is 7" internal depth, right there. Perfect for an AR15, or a DPMS-based LR-308-type recoil system. Edited July 26, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
COBrien Posted July 26, 2018 Report Share Posted July 26, 2018 12 hours ago, 98Z5V said: The photo above is perfect. Right in the middle of the cam pin cutout, just like it should be. It's either gonna be that, or it's 3/16" too short. I looked all over Leapers UTG website, and they don't have a specific .308AR receiver extension. I could only find one receiver extension from them, and it's for the AR15. That's not gonna be the right receiver extension for using the Armalite AR-10 carbine recoil components... These are the two best sources of info on it that I could find: https://www.thefirearmblog.com/blog/2015/03/16/leapers-introduces-6-position-308-ar-receiver-extension/ In this one, straight from Leapers, when you look at all the "related items" in that long list, there is no 308-specific receiver extension... https://leapers.com/index.php?act=prod_detail&status=utg&itemno=TLU001D I'd bet that you have a receiver extension that is 7" internal depth, right there. Perfect for an AR15, or a DPMS-based LR-308-type recoil system. If his RE is 7" internal depth, how would he be able to lock his bolt back with an Armalite buffer? He said it locks back by hand no problem. 3/4" would create one hell of a problem, even by hand... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 26, 2018 Report Share Posted July 26, 2018 35 minutes ago, COBrien said: If his RE is 7" internal depth, how would he be able to lock his bolt back with an Armalite buffer? He said it locks back by hand no problem. 3/4" would create one hell of a problem, even by hand... I have that same question myself. Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 26, 2018 Author Report Share Posted July 26, 2018 Won't be able to get to this for a few days due to work...so don't eat all your popcorn just yet... Quote Link to comment Share on other sites More sharing options...
COBrien Posted July 26, 2018 Report Share Posted July 26, 2018 (edited) 1 hour ago, 98Z5V said: I have that same question myself. I guess my point is, he'd have to have a 7-3/4" receiver extension, with an Armalite buffer, in order to lock it back by hand and not have any carrier strikes inside the lower. Unless the receiver extension is just a RCH shorter than 7-3/4", my money says the extension isn't the problem. EDIT: I'm betting it's just running too dry. Slather that BCG in 15W-50 Mobil 1 for the first 200 rounds (keep the bolt face clean and dry, though...), and I'd bet she'll start running right. Or it's a gas issue... Edited July 26, 2018 by COBrien Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 26, 2018 Report Share Posted July 26, 2018 Nope, I figured it out - that bolt catch is only grabbing the BCG body, and not the bolt face. It doesn't travel rearward enough to catch on the bolt face, and it's probably barely catching that body of the BCG. I'm putting that combination together right now, to try out. Quote Link to comment Share on other sites More sharing options...
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