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Posted: 5/21/2026 4:06:18 PM EDT
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I built an LR-308 a while using mostly DPMS parts. I'm having some ejection issues and want to try a different bolt. I like having a spare BCG, anyway, so I'm looking for one that might help my reliability issues. What are some of the better options available? I'd like to keep the cost under $250, if possible. TIA |
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I use JP High Pressures in my builds. LMT in my LMT. While I don’t have one of their 308 bolts (I have their 556 and PCC BCGs) KAK makes a dual ejector bolt. You could go with one of the “heavies” like Wilson Combat or try Toolcraft. |
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It’s not about how many people you kill, it’s about how many you save.
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I’ve had several LR DPMS, two gave me trouble. Took a while to figure out, but the tip of the hammer was dragging too much on the BCG. 5 minutes with a file fixed them. I guess you’ve pulled the extractor at this point and checked that? |
If life was easy nobody would quit.
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Originally Posted By DVCER: I’ve had several LR DPMS, two gave me trouble. Took a while to figure out, but the tip of the hammer was dragging too much on the BCG. 5 minutes with a file fixed them. I guess you’ve pulled the extractor at this point and checked that? Yes. I had major extraction problems, but finally got them fixed. Now it extracts, but doesn't always eject.  When you say that some filing fixed it, I assume you filed the hammer, correct? |
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Originally Posted By KILLERB6: I use JP High Pressures in my builds. LMT in my LMT. While I don’t have one of their 308 bolts (I have their 556 and PCC BCGs) KAK makes a dual ejector bolt. You could go with one of the “heavies” like Wilson Combat or try Toolcraft. JP and LMT are a little rich for me ATM. I could swing it, but was hoping to find something a little less expensive. Is KAK generally known to make a quality product? I've heard of them before, but I have no experience. Toolcraft came up in my searches, but I also saw something on another forum suggesting that the Toolcraft dual Ejector bolt causes problems in an LR308. I'll take a look at WC. |
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Originally Posted By Bravo_Six: Yes. I had major extraction problems, but finally got them fixed. Now it extracts, but doesn't always eject. When you say that some filing fixed it, I assume you filed the hammer, correct? Just the tip, no pun intended. Where it bears on the bottom of the carrier. Maybe .010”. It’s obvi gotta make contact. Those were RRA 2 stage match triggers. There was just too much contact in my situation. DPMS lowers. It was slowing my bolt enough some cases just dribbled out and jammed up. I didn’t really figure it out myself, somebody here suggested it. |
If life was easy nobody would quit.
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Originally Posted By DVCER: Just the tip, no pun intended. Where it bears on the bottom of the carrier. Maybe .010”. It’s obvi gotta make contact. Those were RRA 2 stage match triggers. There was just too much contact in my situation. DPMS lowers. It was slowing my bolt enough some cases just dribbled out and jammed up. I didn’t really figure it out myself, somebody here suggested it. Originally Posted By DVCER: Originally Posted By Bravo_Six: Yes. I had major extraction problems, but finally got them fixed. Now it extracts, but doesn't always eject. When you say that some filing fixed it, I assume you filed the hammer, correct? Just the tip, no pun intended. Where it bears on the bottom of the carrier. Maybe .010”. It’s obvi gotta make contact. Those were RRA 2 stage match triggers. There was just too much contact in my situation. DPMS lowers. It was slowing my bolt enough some cases just dribbled out and jammed up. I didn’t really figure it out myself, somebody here suggested it. I'll take a look at it. Thanks for the tip! 
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Originally Posted By mouthpiece: Is it gassed correctly? 2 of my Oracles had to have the gas ports opened I have a JP adjustable GB that I adjusted to barely lock back unsuppressed shooting Tula (the weakest ammo that i have). The ejection issues are happening regardless of ammo or suppressor use. |
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On a side note... could you post a few pics of a fired brass case ? ... Looking for any signs of a rough chamber. And remember... steel cased ammo doesn't "release" from the chamber walls as readily as brass cased. So those steel cases might be giving you "false / poor" signs. Is your "current" BCG a DPMS one ? You said... "Now it extracts, but doesn't always eject. " Could you post more specific info ? ... cases don't release from the extractor... BCG doesn't "cycle" far enough back ? And a few pics of the extractor "claw"... looking for rounded outside dges... that allow the case to release easily. 5.56 extractor pics, as an example. 
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
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Originally Posted By bfoosh06: On a side note... could you post a few pics of a fired brass case ? ... Looking for any signs of a rough chamber. And remember... steel cased ammo doesn't "release" from the chamber walls as readily as brass cased. So those steel cases might be giving you "false / poor" signs. Is your "current" BCG a DPMS one ? You said... "Now it extracts, but doesn't always eject. " Could you post more specific info ? ... cases don't release from the extractor... BCG doesn't "cycle" far enough back ? And a few pics of the extractor "claw"... looking for rounded outside dges... that allow the case to release easily. 5.56 extractor pics, as an example. https://www.ar15.com/media/mediaFiles/171545/__________________________________________SuWHaxU-912480.jpg @bfoosh06 Here is a thread from last year where I posted pics of some brass. I thought I also had extractor pics, but I don't see them. https://ar15.com/forums/AR-15/LR-308-extraction-woes/121-790164/ Most of the parts I used, including the BCG, were DPMS. I thought I was being smart by doing this to avoid compatability issues that can happen with different AR308 parts. A parts list is in the linked thread. The ejection problems happen 5-10% of the time. The fired case ends staying in the upper (oriented in the direction of feeding) and it stops the bolt as the bolt moves forward stripping a new round from the mag. Basically, the fired case ends up above the new round with the case head on the bolt face and the case mouth near where the gas tube comes into the upper. The case mouth gets crushed and it jams up the action pretty good. FWIW, I ordered a JP extractor and it fixed the extraction issues. IIRC, the claw on the JP was much more pronounced than the DPMS extractor. At the time of my last post, I was having some ejection issues, but I thought they might be something that goes away with some break in. I've since shot the rifle on a few more occassions and the issue persists. |
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Thank you for the link. My comments are kind of me just thinking out loud, ... so ... Did you ever flex hone the chamber ? And I am not sure what to make of the "smile" shaped gouge... that is not normal. And as mentioned in your link, it is most likely from a sharp edge at the chamber. Tony's pic example should fix that. I use a over sized bore mop, ( that will NOT fit in the chamber, but does make contact with that "edge" ) with JP paste and Kroil, spun via a spare piece of cleaning rod... BE SURE TO CLEAN UP all fuzz , etc PRIOR to allowing the BOLT slamming closed !!!! All that "lint" will lock up a BOLT good n' tight if you dont remove it. Did you ever try a heavier 2.5" buffer ? IE something like this....https://kakindustry.com/lr-308-carbine-buffer-heavy It might be the current cyclic speed is fast enough, the extracted case isn't getting enough time to get out of the way. FWIW... if you try the heavier buffer.... you will most likely need to retune the Adj. GB. What specific mags are you using ? I know PPU 308 brass can be considered "soft".... And I see you tried other brass cased ammo... did those cases have the same "smile" ? FWIW... The JP extractor is probably the best " 308 "extractor out there. So... since the case is pulled out of the chamber, it does sound like your ejector spring is "lacking". ... or the cyclic speed is out running the ejection. Have you tried replacing that ? ... And / or checking for proper / easy function ? |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
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Originally Posted By bfoosh06: Thank you for the link. My comments are kind of me just thinking out loud, ... so ... Did you ever flex hone the chamber ? And I am not sure what to make of the "smile" shaped gouge... that is not normal. And as mentioned in your link, it is most likely from a sharp edge at the chamber. Tony's pic example should fix that. I use a over sized bore mop, ( that will NOT fit in the chamber, but does make contact with that "edge" ) with JP paste and Kroil, spun via a spare piece of cleaning rod... BE SURE TO CLEAN UP all fuzz , etc PRIOR to allowing the BOLT slamming closed !!!! All that "lint" will lock up a BOLT good n' tight if you dont remove it. Did you ever try a heavier 2.5" buffer ? IE something like this....https://kakindustry.com/lr-308-carbine-buffer-heavy It might be the current cyclic speed is fast enough, the extracted case isn't getting enough time to get out of the way. FWIW... if you try the heavier buffer.... you will most likely need to retune the Adj. GB. What specific mags are you using ? I know PPU 308 brass can be considered "soft".... And I see you tried other brass cased ammo... did those cases have the same "smile" ? FWIW... The JP extractor is probably the best " 308 "extractor out there. So... since the case is pulled out of the chamber, it does sound like your ejector spring is "lacking". ... or the cyclic speed is out running the ejection. Have you tried replacing that ? ... And / or checking for proper / easy function ? No. I never flex honed the chamber. The JP extractor seemed to fix the issue and I was not crazy on the idea of taking abrasive to a new barrel. I did not try a heavier buffer, but I do have extra 308 buffers and tungsten weights, so that would be easy for me to try. I will whip one up tonight. Mags were pmags and (I think) Brownells aluminum. |
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Thank You FWIW... I have "polished" many LFAR chambers ( including radius'n the chamber edge ) ... using a snug fitting bore mop, same piece of spare USGI cleaning rod, spun VIA a cordless drill and JP Bore bright with Kroil Penetrating Oil. It only took a few minutes, for me to be happy with the results. It really doesn't take much to do and doesn't ruin the chamber. The JP isn't very abrasive when used with the bore mop and Kroil. So don't think you will FUBAR the chamber... I mean you would REALLY have to be trying to mess it up. Don't forget to check the "current" ejector spring. |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
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