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Posted: 4/12/2017 3:04:41 PM EDT
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It is a PA10 with upper assembly from PSA Gen2 PA10 18" Rifle Length CHF 308 WIN 1:12 15" MI SSK15 - with NiB BCG and Charging Handle. Lower is a PSA Gen1 stripped with a PSA PA10 MOE PLUS Black Lower Build Kit.
Got the rifle to run except once every 3 to 5 rounds, the case does not completely eject from the bolt and the bolt partially chambers the next round with the case still partially attached causing a stoppage. The ejector button pushes the case off the bolt face but the extractor hangs on to the rim and the case does not come off the bolt. Case hangs on at an angle sticking out the ejection port. I have to pull hard on the case to strip it from the bolt. The 2 corners of the extractor actually digs into the rim of the case. The fit between the case rim and the bolt face is very tight. I see brass shavings. Picture is where I manually insert a round onto the bolt and then let the ejector try to push the round off the bolt. I can hold the bolt and try to fling the round off and it will not come off. Some rounds stick on tighter than others. I've only used mil-surp 7.62X51 ammo so far. Port, SA, Hirt. Anyone seen this before? Is this an extractor tolerance problem where the extractor is too tight to the rim and when the ejector pushes the case off the bolt there is not enough clearance and the extractor digs into the rim keeping it from ejecting properly? Thanks. |
| My PA10 extractor was so stiff from the factory it wouldn't ride over the lip of the new round. I would take the extractor out and see how many springs and O-rings are in yours and pull some of them out to see if that helps. Mine runs 100% with just the fat spring, it came from PSA with the fat spring, a thinner one inside that, and two O-rings around them. |
| There is one spring and 2 o-rings. No problem with extraction or the bolt going into battery during firing. Just the extractor would not let go after the ejector pushes the case off its side of the bolt face. Tried just using one o-ring+spring and the case still manually stays on and have to pull it off from the extractor. The extractor was much easier to install with just the one o-ring and spring. Before, with the 2 o-rings and spring, it was very difficult to get the extractor pin to start through the hole on the other side of the bolt. Will give it a try at the range with "reduced" extractor spring to see if makes any difference. Thanks. |
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First, I believe extractor polishing is covered in this thread:
http://www.ar15.com/forums/t_16_4/42_Hellbenders-guides-to-Ultimate-AR15-and-or-AR10.html&page=1 If you decide you want to try a different ejector spring you might try a sprinco. http://www.sprinco.com/tactical.html What buffer and spring system are you using? If you were ejecting cases but getting them caught I would up buffer weight. Given the failure to come off the bolt face I would look into extractor polishing and maybe a new ejector spring. |
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Try some Hornady or Winchester or Remington factory ammo. Did you check headspace yet?
How does the gen 1 lower match up to the gen 2 upper? I have a gen 1 rifle, that has been flawless for about 500 rounds, I had one hiccup with the third pull of the trigger, but since then .........I have run about 500 rounds through this build with no problems..........I have only used factory Remington, Winchester and Hornady Ammo, and my reloads with no problems...........using Mag pul magazines........... |
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I have read (and will be using it myself) that the "DPMS GII extractor kit" solves ejection problems. The kit is proprietary (you have to use the extractor and elastomer bushing together, but they work in any DPMS pattern bolt (not just the GII). Although a bit pricey for what they are (just an extractor plus rubber type compression "bushing"), you may want to give it a try.
ETA: I picked up a couple (2) at Brownell's. They were on sale less than a week ago, and might still be. |
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