Scott76 Posted January 17, 2020 Report Share Posted January 17, 2020 (edited) Greetings gents. First AR308 build, 5th AR platform build overall. Gun specs: Faxon 20" pencil barrel Superlative Arms adjustable gas block Springco Orange extra power carbine buffer spring KAK Industries 5.3oz buffer Toolcraft nickel boron BCG Magpul Pmags Took the thing out for the first time today with intentions of tuning the gas block. Started at 4.5 turns out (normal operation, no blow-by or restriction). Shooting Remington Core-lokt 180gr. I was single loading the mag to make sure the bolt was locking back while I tuned the block. At first, when it did eject, they were coming out at 1 O'clock. Through adding more blow-by I eventually got them to eject at 3 O'clock. The thing is, about every third round it would not eject the case, it would be lying on the mag, sometimes turned 180 degrees. It did this if it was at full power or with blow-by introduced, so I do not believe this to be a gas issue. Also, the bolt locked back every single time as it should. I feel somewhat foolish as I did not clean or lube anything before heading out, with the exception of a quick wipe down. These are all brand new parts. I'm about to tear the bolt down and see if I can find anything, but I'd appreciate a shove in the right direction and any glaring issues with my setup. I feel like I did a great deal of reserch before selecting components so this is pretty disappointing. None of the other AR's I've put together have ever had an issue. Edited January 17, 2020 by Scott76 Quote Link to comment Share on other sites More sharing options...
Ravenworks Posted January 17, 2020 Report Share Posted January 17, 2020 Lube the BCG and shoot the rifle to break it in. Also, you'll want to be careful using ammunition like that as it can slam fire. There is a reason the military requires specific primers. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 17, 2020 Author Report Share Posted January 17, 2020 6 minutes ago, Ravenworks said: Lube the BCG and shoot the rifle to break it in. Also, you'll want to be careful using ammunition like that as it can slam fire. There is a reason the military requires specific primers. What do you mean by ammunition like that? Because of the bullet design? I built this gun primarily to be a hunting rifle, so ammunition with those sort of tips will be used. I was not aware this was an issue in this platform, only heard of that in tube feed lever guns. Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted January 18, 2020 Report Share Posted January 18, 2020 Before you change much, lube the gun... a lot. Shoot it more to break it in. These rifles usually need more lube to start with. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 18, 2020 Author Report Share Posted January 18, 2020 Yeah I’m hopeful that may be it. I pulled it apart and the extractor and ejector seem to be 100%. I lubed the hell out of it and I’ll give her another go. Quote Link to comment Share on other sites More sharing options...
Ravenworks Posted January 18, 2020 Report Share Posted January 18, 2020 Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you’re reloading for a military semi-auto, look to CCI Military primers. *Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential. https://www.cci-ammunition.com/products/primers/primers.aspx?id=30 Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 18, 2020 Author Report Share Posted January 18, 2020 So you’re saying that any ammo in an Semi auto platform is at risk of a slam fire if it’s not utilizing CCI primers? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 18, 2020 Report Share Posted January 18, 2020 2 hours ago, Scott76 said: So you’re saying that any ammo in an Semi auto platform is at risk of a slam fire if it’s not utilizing CCI primers? No. The BCG had to be fully forward, and the bolt needs to be completely locked in the extension, for the firing pin to even reach the primer. Just the inertial force (weight of the firing pin) isn't gonna be enough to set that primer off. The parts you listed are smart parts to use - what's the receiver extension, though? It's a Carbine extension, for sure - but what's the internal depth of it? What brand of upper and lower? Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 18, 2020 Author Report Share Posted January 18, 2020 Live Free Armory upper and lower Daniel Defense buttstock on a standard AR15 receiver extension. Quote Link to comment Share on other sites More sharing options...
washguy Posted January 18, 2020 Report Share Posted January 18, 2020 Ravenworks Why would you post this about slam firings in this post on a guy that is having probs with cycling? That post isnt helpful at all for this mans problemo... why dont you remove it as it is about as off the charts as you can get for his problem.....Wash Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 19, 2020 Report Share Posted January 19, 2020 (edited) 9 hours ago, Scott76 said: Live Free Armory upper and lower Daniel Defense buttstock on a standard AR15 receiver extension. Measure the internal depth of that receiver extension. It should be 7.000" internal depth, and not even a little over that. If it follows the Armalite M15 spec, it will be 6 15/16" internal depth. I had a receiver extension from a well-respected company measure in at 7.100" internal depth, and it created the exact same problem you're having right now... Live Free sells good parts - their uppers and lowers are made by Matrix Aerospace. Edited January 19, 2020 by 98Z5V Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 Well dang. I never thought that would create an issue. I can’t even recall the extension manufacturer, I think I just bought whatever off of Brownells or Ranier. I’ll put a tape on it as soon as I get home. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 19, 2020 Report Share Posted January 19, 2020 Just now, Scott76 said: Well dang. I never thought that would create an issue. I can’t even recall the extension manufacturer, I think I just bought whatever off of Brownells or Ranier. I’ll put a tape on it as soon as I get home. Put the tape IN it - you need the internal depth, that's what counts. Measure at the top, because some of these things have a "flare" at the bottom portion, to better catch the buffer retainer. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 Yep, that’s the plan. Quote Link to comment Share on other sites More sharing options...
Ravenworks Posted January 19, 2020 Report Share Posted January 19, 2020 On 1/17/2020 at 3:43 PM, Scott76 said: I feel somewhat foolish as I did not clean or lube anything before heading out, with the exception of a quick wipe down. These are all brand new parts. I'm about to tear the bolt down and see if I can find anything, but I'd appreciate a shove in the right direction and any glaring issues with my setup. I feel like I did a great deal of reserch before selecting components so this is pretty disappointing. I'm not going to get involved with the other post because he knows what direction this needs to go. But I am going to ask a few simple questions to make you think. 1)-Did you headspace this after you put everything together? 2)-did you patch the bore or check it for obstructions? 3)- you really need to do a detailed oiling until things get broken in. 2 hours ago, washguy said: Ravenworks Why would you post this about slam firings in this post on a guy that is having probs with cycling? That post isnt helpful at all for this mans problemo... why dont you remove it as it is about as off the charts as you can get for his problem.....Wash Why did I post it, because it's something he should be aware of. Remington Core-lokt 180gr ammunition is not particularly happy being stripped from a mag and shoved up the feed ramps designed for ball type ammo. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 (edited) 3 minutes ago, Ravenworks said: I'm not going to get involved with the other post because he knows what direction this needs to go. But I am going to ask a few simple questions to make you think. 1)-Did you headspace this after you put everything together? 2)-did you patch the bore or check it for obstructions? 3)- you really need to do a detailed oiling until things get broken in. Why did I post it, because it's something he should be aware of. Remington Core-lokt 180gr ammunition is not particularly happy being stripped from a mag and shoved up the feed ramps designed for ball type ammo. 1) No. I know I should have but with a new barrel and new BCG I thought the odds were in my favor and rolled the dice. 2) yes 3) Done and ready for next range trip. I have 200 rounds of FMJ on the way to eliminate variables. Edited January 19, 2020 by Scott76 Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 Okay measured the internal of the receiver extension. 6-15/16th Quote Link to comment Share on other sites More sharing options...
98Z5V Posted January 19, 2020 Report Share Posted January 19, 2020 28 minutes ago, Scott76 said: Okay measured the internal of the receiver extension. 6-15/16th It's a 100% gas problem, then - it is NOT a recoil problem, at all. It's all in the gas. On 1/17/2020 at 1:43 PM, Scott76 said: Took the thing out for the first time today with intentions of tuning the gas block. Started at 4.5 turns out (normal operation, no blow-by or restriction). Shooting Remington Core-lokt 180gr. I was single loading the mag to make sure the bolt was locking back while I tuned the block. At first, when it did eject, they were coming out at 1 O'clock. Through adding more blow-by I eventually got them to eject at 3 O'clock. The thing is, about every third round it would not eject the case, it would be lying on the mag, sometimes turned 180 degrees. It did this if it was at full power or with blow-by introduced, so I do not believe this to be a gas issue. Also, the bolt locked back every single time as it should. I feel somewhat foolish as I did not clean or lube anything before heading out, with the exception of a quick wipe down. These are all brand new parts. I'm about to tear the bolt down and see if I can find anything, but I'd appreciate a shove in the right direction and any glaring issues with my setup. You start an adjustable gas block WIDE OPEN. All the way, no joke, not kidding you. You get the gun WET, you break the gun in, THEN you start adjusting gas down to your desirable level. All those steps, in that order. That's the only way totune an adjustable gas block on a brand new build If you don't start an adjustable gas block WIDE OPEN, full-on - then you'll never, ever know if the gas port in the barrel is even large enough in the first place - which is a proven issue on .308ARs. If you wide-open it on a broken in gun - and it STILL doesn't hold the bolt to the rear on a single round - that gas port needs to be drilled up, right then. For now, stop looking at ejection patterns, and break the gun in. Get it wet, break it in, THEN play with the adjustable gasblock. This is why we don't complicate shiit with complicated shiit. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted January 19, 2020 Report Share Posted January 19, 2020 (edited) 11 hours ago, 98Z5V said: Live Free sells good parts - their uppers and lowers are made by Matrix Aerospace. That may have changed, @buttonbuck had a rifle he was told they made on new machines. The pictures of their sets are no longer the Armalite cut both of my matrix sets have, one from Chris and one from Primary Arms a couple years later. https://www.livefreearmory.com/receiver-sets.php Doesn't clear up any what was made where by who but it is an interesting read, makes me think, hell yeah, AMERICA! https://www.livefreearmory.com/our-story.php On 1/17/2020 at 2:43 PM, Scott76 said: The thing is, about every third round it would not eject the case, it would be lying on the mag, sometimes turned 180 degrees. Back to your topic. For sure start out with lots of lube and gas wide open. I have seen an issue sounding very similar to what you describe go away with an extractor and ejector spring set swap. I put in some spare Armalite parts from a kit and it ran, I have also tried it and not gotten results on other rifles. Even if it doesn't help it never hurts to have spare springs. Edited January 19, 2020 by jtallen83 clarity Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 8 hours ago, 98Z5V said: It's a 100% gas problem, then - it is NOT a recoil problem, at all. It's all in the gas. You start an adjustable gas block WIDE OPEN. All the way, no joke, not kidding you. You get the gun WET, you break the gun in, THEN you start adjusting gas down to your desirable level. All those steps, in that order. That's the only way totune an adjustable gas block on a brand new build If you don't start an adjustable gas block WIDE OPEN, full-on - then you'll never, ever know if the gas port in the barrel is even large enough in the first place - which is a proven issue on .308ARs. If you wide-open it on a broken in gun - and it STILL doesn't hold the bolt to the rear on a single round - that gas port needs to be drilled up, right then. For now, stop looking at ejection patterns, and break the gun in. Get it wet, break it in, THEN play with the adjustable gasblock. This is why we don't complicate shiit with complicated shiit. I may have not said this clearly. 4.5 turns IS wide open. Zero turns out is completely restricted, the port is totally closed. 4.5 turns it is functioning like a standard non adjustable gas block. Also, as I said - I had failures at wide open, and failures at blow by settings. It didn’t matter. A couple times it would fail, and I’d load another round without changing anything, and then it would eject. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted January 19, 2020 Report Share Posted January 19, 2020 On 1/17/2020 at 2:43 PM, Scott76 said: Superlative Arms adjustable gas block Curious where you end up on the blow by side. I tried a Superlative on a 16 inch rifle gas 308 and could not adjust it far enough to stop function. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 (edited) 21 minutes ago, jtallen83 said: Curious where you end up on the blow by side. I tried a Superlative on a 16 inch rifle gas 308 and could not adjust it far enough to stop function. Honestly man I was having the same experience. I kept introducing more and more blow by and it kept locking back but then my focus turned to the ejection issue. Plus my hands were freezing and I forgot gloves so I didn’t get a long test in. Only shot 20 rounds. Gotta love Wisconsin in Jan. Edited January 19, 2020 by Scott76 Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted January 19, 2020 Report Share Posted January 19, 2020 20 minutes ago, Scott76 said: Plus my hands were freezing and I forgot gloves so I didn’t get a long test in. Only shot 20 rounds. Gotta love Wisconsin in Jan. Was the rifle warm to start? Cold weather and new parts, I wouldn't make any big changes till you get a few more boxes down range, a bunch of hand cycling maybe. Quote Link to comment Share on other sites More sharing options...
Scott76 Posted January 19, 2020 Author Report Share Posted January 19, 2020 Warm as in it was in my house and truck before I got to my buddies place to shoot. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted January 19, 2020 Report Share Posted January 19, 2020 How far are you from DuBay Shores ? We got together at the Duane L. Corbin range. Quote Link to comment Share on other sites More sharing options...
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