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6/4/2007 2:56:56 PM EDT
I am reading the other threads and I hope I can get a specific response. I bought a new Kotonic 18 6.8 upper and finaly had a chance to shoot it. I am running into a problem, which I e-mailed Kotonics about. I have full confidence I will get a reply but in the meantime, I hope you guys can get me on the right track.

I am using Hornady 110 grain JHP with a 5 round c product mag, full length fixed stock with a endine full length buffer and a gas buster handle.

So I finaly get some rounds for it. Right after the 1st shot, shells fails to eject. The bolt stay put just far back enuff to expose 1/4 of the shell's rear. The bolt ejector is right over the magazine. With a little tug, the shells spits out but the problems persists. I wish I had enuff rounds to test it without the mag, to rule that out.

With no rounds in it, I manually test the bolt carrier and it pull back smooth as it can be. When I feed a round and manually cycle rounds, it feels a bit tight when the bolt is pull out of the barrel/feed ramp area. After many times testing, the round come out marred, scratched.

I am not an Ar-15 guru but I am hoping its the rounds? Or will it smooth out in time? Or do you think the feedramp area needs some type of smoothing out? I hate to have work done to smooth out the action on an otherwise awesome upper. If so, can I do it myself? I hope I dont need to send it back for some work.
6/4/2007 3:04:22 PM EDT
[#1]
This isn't meant to sound stupid and/or insulting, but did you clean and lube everything before firing?  I have been guilty of assembling uppers and forgetting to give them a good initial lubing, often resulting in short stroking and other kinds of malfunctions.  Get any assembly lube and grit out of it, then give it another try with a liberal coating of lubricant.  That's the easiest thing to check first.
6/4/2007 3:14:45 PM EDT
[#2]
have you tried a normal buffer/spring setup?

extractor spring checked or tried an O-ring?

something hanging (mag, chamber/BCG, chamber)?
6/4/2007 7:15:37 PM EDT
[#3]
O-ring installed on the bolt extractor. This being my 1st non-piston rifle, I'll clean and lube the set up. I hope that will cure it. Yea, I do feel silly.
6/4/2007 7:28:11 PM EDT
[#4]
ive got a magpul prs stock on my 6.8 with an endine rifle buffer and it works great. in my 5.56 rifle the endine wouldnt work. so you could try to change that and see if it helps.
6/5/2007 5:07:50 PM EDT
[#5]
Clean and lube it good,run it wet.Good luck
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