9mm extraction issues

[landyacht302614]

I just recently started having problems with my 9mm build after about a year of shooting it and was wondering if someone could help diagnose the problem.

Just recently I swapped out a 10.5 inch green mountain barrel for a 16 inch green mountain barrel and after taking it to the range, its having issues extracting.

It will sporadically run good then it will chamber the next round and the bolt will close but the extractor will not hook around the case for some reason. I can pull the CH all the way to the rear, release it letting it slam home and will not pick up the round unless sometimes doing that 3 to 4 times. Then others times I have to pull out my pocket knife and pry it out.

I have taken the extractor out and cleaned it thoroughly and it brought up the extraction rate up to about maybe 50%. As you can see from the pictures its clean with no buildup on it anymore. Ive also cleaned the channel the extractor sits in.

I can take a case and manually put it on the bolt face and it grabs the case just fine, looks and feels like a lot of engagement.

I even swapped barrels back to the original 10.5 inch and Im still having the issue so not an out of spec chamber on the new barrel.

Is it possible that the buffer spring has just worn to the point where it doesnt have enough umph behind it anymore to close the bolt hard enough to get that extractor around the case? Or is this a case of a worn extractor?

Here are the specs

CMMG bolt

Green Mountain barrel

Hahn top loading mag block

Brownells modified uzi mags with BHO tab on back of follower

Ammo is 115 gr FMJ reloads of mine, taper crimped to a .375"

Standard carbine buffer spring

Spikes heavy 9mm buffer
12632810_10208342410617327_1483139974_o.jpg12656235_10208342411097339_461280461_o.jpg12656414_10208342410977336_1720074485_o.jpg12669214_10208342410817332_2010829609_o.jpg

[mister2]

I also have extraction/ejection problems. Basically ran a hundred rounds or so, with no problems; but now sporadically fails to extract properly so the empty gets caught by the incoming round. All this time I have been using steel case ammo, which I believe is at least part of the problem.

So I polished the chamber with bore cleaner on a cloth with a low-speed drill, made sure the chamber was lubricated and have been able to get the polymer steel cases to run, but not the lacquer type. So , polishing the chamber is giving marginal results and the only other possibility I can think of is the extractor. Two things: my steel cases show tiny dents where the extractor rode over the edge to hook the rim, so I know the bolt is going fast enough and the extractor tension is good, perhaps too good. Secondly, I'm wondering whether the inside angle of the extractor is perfectly flat against the rim, or maybe the cutout curve allows the extractor to slip off too easily. So even with high tension, the extractor still can't hang on to the round.

As to your issue of the extractor not going over the rim, perhaps your extractor tension is too high, and you made it even higher? Are you using brass or steel cases? If it won't go over the rim, will your hammer still drop? If it does, then it releases out of battery, which is normally not a good thing. Fortunately, because of the firing pin design, I don't believe it will protrude far enough to ignite the primer when it's still out of battery.

In any case, if I continue to have problems, I might try altering the angle of the extractor or maybe try a brand new extractor and see if that makes a difference.

Let us know if you have new developments.

MR2