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Posted: 3/30/2005 7:38:56 AM EDT
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I took a virgin 24" stainless bull upper to the range today to set the scope and had some big ejection problems. I had bought a hard chrome plated carrier and bolt for it and I think it may have to go into the trash pile. It shot great with lake city but the bolt only came back about 1/4".I took the bolt out of the other ar and it ejected fine but jammed trying to load the next round(every time). I cleaned everyting off the chrome bolt(oil and stuff)cleaned the the bore and the chamber.shot a few more and the shells came about 3/4 of the way out but still wouldn't come all the way out.And I also noticed that the case mouth on 8 out of 10 rnds had split. Any ideas or suggestions would be welcomed. |
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Is this a recently built rifle/upper? If so was the headspace checked. Are you using 5.56mm rounds in a SAAMI spec 223 chamber???? (see info up top here: www.ammo-oracle.com) Mike |
| I have the problem narrowed down to the gas system.It looks asthough it is not getting enough pressure to reset the trigger.The carrier comes back to the point of resetting the trigger and stops.Any tips on how to make sure the gas port , gas block and tube are lined up correctly? |
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Chrome plated carriers can be a nightmare since they are stock units that are plated. This builds up the OD on the parts and causes binding (key down the upper reciever track). Next on the gas block, Make sure that the block port is aligned with the barrel block port. Often, you need to mic both the barrel, and the block and use pencil marks to get the two to blindly mate. Note not only the rotation index on the barrel, but also the amount that the block need to sit off the barrel stop shoulder to align the ports (front to back). Lastly, since the plating also build up the carrier, check the back of the trigger behind the disco hook for signs of the hammer tail making contact with the trigger. If you find a indent/line, you will need to take .040 off the hammer tail. Bottom line, once you have went back and re-checked the build, run the rifle with 223 ammo, and kept the upper bearing surfaces well lubed with CLP until theparts mate (read either the key sides either polishing out, or the key enlarging the receiver tracking slot until it will free run without binding). |
| Uhhhhhhhhhggggggggggggggggg!!!!!!!!!!!!!!!.I'm such a nitwit.I just broke everything down AGAIN and checked a few things.I wish I would have checked the gas port a week agao.That was the problem.The gas port holes were off 1/2 a hole only letting it get a portion to the blow back that it needed. I'm such a retard.........Thanks for the input guys but I think I just need to go back to evil black rifle kindergarten.LMAO hinking.gif |
| It looks like I might not be as dumb as I thought I was.......or maybe I am.It's still not extracting but now I have noticed two lines(gouges)on the case neck.The marks match perfectly with the locking lugs.Is it possible that the empty could be catching on the back side of the lugs enough to hold up the process long enough to let enough gas get by that it can't finish the cycle? |
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