Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Posted: 5/11/2003 8:40:27 AM EDT
I have a 16" no name upper with a Colt bolt and carrier. I can go through about 4 or 5 mags of 30 rounds with no problems. It seems like when the rifle gets hot every other round is a failure to extract. No matter what ammo I use SA surplus,LC,or Q3131. The case of every other round is stuck in the chamber with the rim of the case head damaged or completely torn off where the extractor has grabbed it. THIS SUCKS!
Please help me fix my baby.
Link Posted: 5/11/2003 1:38:35 PM EDT
Originally Posted By gungoat34: I have a 16" no name upper with a Colt bolt and carrier.
View Quote
Any manufacturer markings on the barrel?
Link Posted: 5/12/2003 8:41:23 AM EDT
Man, lots of things it could be. Your problem is poor extraction. High pressure makes for extraction with difficulty. Can be because of ammo, chamber or throat. Rough and out-of-shape chambers also extract with difficulty. Dirty chambers can also be the problem. Then thre is the classic problem of carbines being a bit too vigorous. Examine your cases for evidence of high pressure and out of shape chambers. Check diameters of fired cases against those of your unfired ones. Check for signs of a rough chamber. Is the buffer correct? Both shorties and full size stocks should have buffers with weights that you can feel shifting when you shake it. Did you just buy it, or have you had a successful history before it started misbehaving? Get back to us on that stuff, and we can help you get it sorted out.
Link Posted: 5/12/2003 8:48:53 AM EDT
Sell that "perfectly good upper" and buy a new one.
Link Posted: 5/12/2003 12:33:09 PM EDT
You need to polish the chamber.
Link Posted: 5/12/2003 5:09:17 PM EDT
This upper is marked on the side of the front sight assy. C99 RI 2 I purchased the upper new it failed to extract occasionally, but only with SA surplus. Now it does it with everything. The spent cases are all normal when compared with live rounds, with the exception of the case heads where the extractor grabs them. I do have the correct buffer installed. I think that covers all the questions. What now guys? Thank you very much for your responses. Ken
Link Posted: 5/13/2003 6:55:45 PM EDT
I think that the fact that it was occasional and is now getting worse suggests either a wear issue or a cleaning/roughness problem.
Link Posted: 5/16/2003 1:05:34 AM EDT
Sure sounds like a Chamber cleaning / polishing / lacquer buildup issue, to me. Using Wolf / Lacquered ammo? If your chamber is very tight-to-spec to begin with, a little fouling or buildup, + heat would very easily produce the problem you've described.
Link Posted: 5/16/2003 3:53:06 AM EDT
Could it be you have a .223 chamber instead of a 5.56?
Link Posted: 5/16/2003 5:29:37 PM EDT
It is a 5.56 chamber. I don't use Wolf ammo. Last night I took an electric drill and a chamber brush and cleaned the crap out of the chamber. There was quite a bit of buildup there. Sunday, I will take it to the range and see what happens. I will let you all know sunday night. Thanks again. Ken
Link Posted: 5/17/2003 10:20:32 AM EDT
Spinning a chamber brush (metal) in the chamber with a drill is a bad practice. The bristles will grove the chamber walls as they are spun. A better solution is to use a 30cal cotton mop with cleaner, or a very fine polishing compound, if your plan is to polish the chamber walls. Normally I just suggest that a good copper solvent or CLP is use only. This prevents the chamber/ throat from any wear of repeated cleaning using a spinning mop. Hope this helps.
Top Top