aadavis94 Posted March 1, 2020 Report Share Posted March 1, 2020 So I've built an AR .308 and I'm having FTE and FTF issues Aero precision: M5 upper, lower and hand guard, low profile .750 gas block Armalite: carbine length gas tube 6 position buffer tube, spring and buffer 18 inch stainless fluted barrel (specs in pic below) Ke arms slt2 trigger. 10 round pmag. VG6 lamba muzzle Device Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted March 1, 2020 Report Share Posted March 1, 2020 You look very dry in there. Are these factory ammo or reloads. These rifles tend to need a break in period, sometimes up to 200 rds. Lube them wet, like dripping, and shoot good factory ammo. Sometimes heavier grain is better but not necessary. Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 1, 2020 Author Report Share Posted March 1, 2020 I'm shooting factory loads, 155-180 grain. I've probably put about 75-100 rounds through it so far. Next time I go out I will make sure to lube her up even more. I've been using gun grease but will try oil next time. Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted March 1, 2020 Report Share Posted March 1, 2020 Just so we are sure, that is an Armalite carbine buffer, tube and spring. Correct? Quote Link to comment Share on other sites More sharing options...
Radioactive Posted March 2, 2020 Report Share Posted March 2, 2020 I agree she looks dry will it lock the bolt back on last round if you load 1 round in the mag? id start by looking at the recoil system after lubing the poop out of it Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 12 minutes ago, Armed Eye Doc said: Just so we are sure, that is an Armalite carbine buffer, tube and spring. Correct? Yes it is Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 6 minutes ago, Radioactive said: I agree she looks dry will it lock the bolt back on last round if you load 1 round in the mag? id start by looking at the recoil system after lubing the poop out of it Idk if it locks back or not after the last round. I am going to lube her up real good and go try again next weekend. Quote Link to comment Share on other sites More sharing options...
Ravenworks Posted March 2, 2020 Report Share Posted March 2, 2020 (edited) Parts list says Carbine length gas tube and the barrel says Mid Length gas system? Edited March 2, 2020 by Ravenworks Quote Link to comment Share on other sites More sharing options...
washguy Posted March 2, 2020 Report Share Posted March 2, 2020 2 minutes ago, Ravenworks said: Carbine length gas tube and the barrel says Mid Length gas system? just like Raven said....if your barrel is a mid length gas system a carbine gas tube will be too short..... look at all the hot gas marks in your chamber area. You must be able to have the bcg lock back on the last round...thats a major function check.....not locking back on the bolt catch will reveal problemos in the gas/recoil system. In the pic the gas tube looks to be halfway across the clam shell looking indent as it should be....she needs more lube fer sure.... Wash Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted March 2, 2020 Report Share Posted March 2, 2020 4 hours ago, aadavis94 said: Gas tube looks fine. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2020 Report Share Posted March 2, 2020 51 minutes ago, Ravenworks said: Parts list says Carbine length gas tube and the barrel says Mid Length gas system? Armalite AR-10 Carbine Gas Tube was spec'd in the list. 38 minutes ago, washguy said: just like Raven said....if your barrel is a mid length gas system a carbine gas tube will be too short..... look at all the hot gas marks in your chamber area. You must be able to have the bcg lock back on the last round...thats a major function check.....not locking back on the bolt catch will reveal problemos in the gas/recoil system. In the pic the gas tube looks to be halfway across the clam shell looking indent as it should be....she needs more lube fer sure.... Wash The Armalite AR-10 Carbine Gas tube is 12 1/16" long. The AR15 midlength gas tube is shorter. The pic that Doc quoted clearly shows that the gas tube is perfect in this gun/combination - ends directly in the middle of the cam pin cutout, where it should. An AR15 midlength gas tube would have been too short, with this combination. OP, what's your gas port diameter? It's too small. I'm betting it's around 0.070", and it needs to be 0.080"~0.085" for that list of barrel specs. Check your gas port diameter, and get ready to drill it up. Everything else in your parts lists looks good, and your failures are what I've seen from too-small gas ports. Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 3 hours ago, 98Z5V said: Armalite AR-10 Carbine Gas Tube was spec'd in the list. The Armalite AR-10 Carbine Gas tube is 12 1/16" long. The AR15 midlength gas tube is shorter. The pic that Doc quoted clearly shows that the gas tube is perfect in this gun/combination - ends directly in the middle of the cam pin cutout, where it should. An AR15 midlength gas tube would have been too short, with this combination. OP, what's your gas port diameter? It's too small. I'm betting it's around 0.070", and it needs to be 0.080"~0.085" for that list of barrel specs. Check your gas port diameter, and get ready to drill it up. Everything else in your parts lists looks good, and your failures are what I've seen from too-small gas ports. gas port is reading 0.085 Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2020 Report Share Posted March 2, 2020 Right where it needs to be. Doesn't look like you have any issues, hardware-wise. Run that thing wet, like @edgecrusher stated. You don't have any parts-issues. The Armalite AR-10 Carbine Recoil System is solid. The barrel specs meet what they need to meet, to make a .308AR 18" MIdlength gas gun run. You have an Aero BCG in there, so the BCG doesn't necessarily suck - it's good, it's actually a ToolCraft BCG. Pull your extractor from the bolt and check what you have for an extractor spring setup. That's the last thing to check, hardware-wise. On the off-chance, check that your ejector is working. Other than that, run it wet, and run alot of rounds through it wet. Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 7 minutes ago, 98Z5V said: Right where it needs to be. Doesn't look like you have any issues, hardware-wise. Run that thing wet, like @edgecrusher stated. You don't have any parts-issues. The Armalite AR-10 Carbine Recoil System is solid. The barrel specs meet what they need to meet, to make a .308AR 18" MIdlength gas gun run. You have an Aero BCG in there, so the BCG doesn't necessarily suck - it's good, it's actually a ToolCraft BCG. Pull your extractor from the bolt and check what you have for an extractor spring setup. That's the last thing to check, hardware-wise. On the off-chance, check that your ejector is working. Other than that, run it wet, and run alot of rounds through it wet. Pulled my bcg apart. Does this look right? I went to pull my ejector out and it shot into deep space orbit so it looks like I'm ordering a new one of those 😅 Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2020 Report Share Posted March 2, 2020 (edited) 3 minutes ago, aadavis94 said: Pulled my bcg apart. Does this look right? I went to pull my ejector out and it shot into deep space orbit so it looks like I'm ordering a new one of those 😅 Looks perfect, for the extractor - just like ToolCraft builds them, with dual o-rings. You don't have an extractor issue, at all. As for that ejector - we now may never know... But shiit happens... and we get it... Your ejector ejected, one last time, so it did it's job... Edited March 2, 2020 by 98Z5V Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 4 minutes ago, 98Z5V said: Looks perfect, for the extractor - just like ToolCraft builds them, with dual o-rings. You don't have an extractor issue, at all. As for that ejector - we now may never know... But shiit happens... and we get it... Your ejector ejected, one last time, so it did it's job... Where is the best place to order an ejector from? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2020 Report Share Posted March 2, 2020 2 minutes ago, aadavis94 said: Where is the best place to order an ejector from? Right here - it's listed as out of stock right now - but call them on the phone... Trust me. Call them, and talk to them, and see if you can get Armalite Part # EA6070... This one: https://www.armalite.com/product/ea6070-ar10-ejector-replacement-kit/ LOCAL: 623-780-1050 TOLL FREE: 800-336-0184 Quote Link to comment Share on other sites More sharing options...
aadavis94 Posted March 2, 2020 Author Report Share Posted March 2, 2020 2 minutes ago, 98Z5V said: Right here - it's listed as out of stock right now - but call them on the phone... Trust me. Call them, and talk to them, and see if you can get Armalite Part # EA6070... This one: https://www.armalite.com/product/ea6070-ar10-ejector-replacement-kit/ LOCAL: 623-780-1050 TOLL FREE: 800-336-0184 Thank you!! Quote Link to comment Share on other sites More sharing options...
RedRiverII Posted March 2, 2020 Report Share Posted March 2, 2020 New magazines? Which rounds are FTE, 1st round, 2nd round? Load 8 and fire. It happened to me with new mags this past week, loaded 30 FTE, load 28 no problem. Quote Link to comment Share on other sites More sharing options...
montanamac Posted March 3, 2020 Report Share Posted March 3, 2020 Hasn't anybody else noticed this picture from the OP's original post? A case that hasn't ejected jammed with a cartridge that has been partially chambered. That seems to me to me an issue with ejection, not gassing or lubrication. It looks like the rifle went through the extraction properly but didn't eject the case at all. The bolt carrier went far enough back to strip a new cartridge off of the magazine and pushed the new cartridge forward in to the chamber until the bolt was stopped by both the old fired case that had not been ejected and the new fresh cartridge. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 4, 2020 Report Share Posted March 4, 2020 (edited) 10 hours ago, montanamac said: Hasn't anybody else noticed this picture from the OP's original post? A case that hasn't ejected jammed with a cartridge that has been partially chambered. That seems to me to me an issue with ejection, not gassing or lubrication. It looks like the rifle went through the extraction properly but didn't eject the case at all. The bolt carrier went far enough back to strip a new cartridge off of the magazine and pushed the new cartridge forward in to the chamber until the bolt was stopped by both the old fired case that had not been ejected and the new fresh cartridge. Yeah, I looked at that pic specifically. Ejection in these things is all about whether your gas system is what it needs to be, and your recoil system is what it needs to be - if they're not, your ejection is either wild or mild - if those two systems aren't prefectly balanced. This isn't AR15-world, where everything had a definitive spec to meet. Hell, I can break in a new AR15 bone dry, zero lube. Not so with a .308AR. So, first, we here went through the details of this OPs gun - it's straight. He built it right. Only thing left - might be that ejector, since we can't confirm that - but we can confirm, through posted pics, that the rifle looks dry. That pic you quoted looks like what happens with a dry .308AR gun - but you have to find out the hardware situation first, which we did. We eliminated everything we could eliminate. Lube it, run it with factory, quality ammo, and break it in... Edited March 4, 2020 by 98Z5V Quote Link to comment Share on other sites More sharing options...
Albroswift Posted March 5, 2020 Report Share Posted March 5, 2020 On 3/1/2020 at 8:59 PM, aadavis94 said: Where is the best place to order an ejector from? I like the KAK, running them in 3 BCG's so far. https://www.kakindustry.com/kak-bcg-ejector-308 Sprinco has great springs. Also, after loosing a couple I bought the tool https://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bolt-tools/ejector-tools/308-ar-bolt-ejector-tool-prod72380.aspx Quote Link to comment Share on other sites More sharing options...
no_name Posted March 6, 2020 Report Share Posted March 6, 2020 @aadavis94 When it doesn't fail to extract, where does the brass land? Quote Link to comment Share on other sites More sharing options...
montanamac Posted March 6, 2020 Report Share Posted March 6, 2020 (edited) Personally I don't agree that running too dry is a problem, I did it all the time in the military, it was far better than worrying about sand jamming the action. Ejection is ejection, the mechanical action of ejecting is pretty simple and directly involves the ejector and spring. Having lost the old one means you'll never know if it was a problem but if installing a new one seems to fix the issue then it's a pretty good bet that it was the problem. But I do agree that timing is critical in any gas operated rifle and there could be a problem with how much gas there is, the magazine or mag follower spring, or the recoil parts. Any of those could change the timing of the BCG and how it interacts with the ammo. For all I know it could be the extractor, maybe it's too short and the case is slipping out from under it while it's being pushed out by the ejector. That would be hard to detect when hand operating the rifle but with the high momentum and speed of normal operation it could occur. Edited March 6, 2020 by montanamac Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted March 6, 2020 Report Share Posted March 6, 2020 25 minutes ago, montanamac said: Personally I don't agree that running too dry is a problem, I did it all the time in the military, it was far better than worrying about sand jamming the action. Was the weapon you were carrying in the military a variant of the large AR platform, or the small AR platform? If you're basing your logic off the small AR platform, the large AR isn't the same animal. It's been well born out for most of the life of this forum that heavy lubrication is a key to getting this platform to run well initially. After the rifle has been broken in and the moving parts play more nicely, it's not quite as critical, but it's still important. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.