A week or two ago I installed the usual upgraded extractor spring set: black insert, stronger spring and the black Crane o-ring. I was not having any extractor problems, but I figured I may as well get them since I was ordering a bunch of other stuff, anyway. The rifle is a CMMG 16" midlength, standard front sight base/gas block, I have had zero malfunctions with it before today, it has about 700 through it.
Today was the first time I fired the rifle with the new parts, and I had failure to eject problems with EVERY round I fired. The extractor would not let of the casing, and it jammed against the locking lug area when the bolt came forward again. After a few cycles of this, I removed the o-ring which helped tremendously. It worked pretty well, but over the next hour or so there were a couple stovepipes. I did not have my old blue insert and spring with me at the range, so I had to deal with the black one. Unfortunately I lost the o-ring at the range, but that's not the end of the world.
As I mentioned before, I have had no problems with this rifle before this. I thought maybe the greatly increased extractor strength is not recommended for midlegnth gas systems, but when I searched on the forum and I saw that people do it with no problems. All the mags I used have worked fine in the past, and they worked fine with the o-ring removed (stovepipes happened with multiple mags), so I think I can rule mag problems out. I have noticed what may be signs of slight gas leaking from the front sight base, but I have never had short stroking problems before. I didn't think of it at the range, but I wish I had tried the 1 round in the mag thing before I removed the o-ring.
Any ideas? Might this be an indicator of other problems?


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