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Posted: 9/26/2016 11:00:58 AM EDT
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FNG here, so bear with me, but I recently finished a Broken Armory 80% 308 build and I'm having feeding problems. I've done a lot of googling, and found a guy with a similar problem here back in '14, but he never posted a resolution. https://www.ar15.com/archive/topic.html?b=3&f=66&t=661024
Parts: -Broken Armory 80% lower -Aero Upper -Aero Nickel bolt carrier group -24" heavy bull barrel -DPMS LR-308 buffer -DPMS extension buffer tube with Magpul PRS 308 stock -Tubb flat wire AR10 spring -Magpul 10 & 20 round mags. Tried a friend's metal one too 1 round mag test: If I charge the handle and let it fly, 50% of the time the round will jam. I seem to have more success locking the bolt back and letting it go with the bolt catch, than using the charging handle. Once round is chambered, it always fires and ejects perfectly. Bolt always locks back. Sometimes I can make it through 5-6 rounds before a jam. Fuller magazines seem to help. Also, if I apply pressure to the bottom of the mag, that seems to eliminate the problem. First rounds through the gun were soft nosed hollow points. Thought that was my problem, so I switched to FMJ's and polished the feed ramps. Upper receiver and barrel have m4 feed ramp cuts in them. When I manually charge the bolt with the handle, you can see, there's only 1/16" of the bolt coming in contact with the back of the round... Compared to my store bought Daniel Defense 556, where a whole lug grabs the round. Don't know if I'm dealing with an out of spec lower, or what, but I could really use some advice. Pictures posted below -Brian |
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I'm having the same issue with one out of three clone builds.
What mags are you using? I'm using the Magpul Gen3 7.62x51 20rd mags. Ballistic Advantage 18" HBAR rifle and an ALPHA nitride 308 BCG, Aero M5 upper, UTG Pro 15" Keymod HG, Standard 308 buffer and spring. After getting the exact same FTF issues form all three rifles, I took them home and broke then down, disassembled the BCG, lubed the crap out of the upper, Buffer tube (had one buffer getting hung up in the tube), and the BCG. Two out of three are functioning ok now, they won't feed and I get the same jam if I try to chamber the round while the turned on its side (ejection port facing up). It seems that the other two have WORKED in, but this last one has more rounds through it and still the same issue. I'm thinking its the Gen3 mags. |
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