Where were we?

[Paul45LC]

After mentioning my new upper's tendency to occasionally fail to eject the empty before picking up the next round, Variable suggested that the extractor might be excessively sharp or have burrs. Thanks. ( thanks also to the guy that seconded the suggestion, but who's name eludes me )

I had a chance to take a look, and the dang extractor was razor sharp. Opting to err on the side of caution, I burnished the edges. I can always hit it again later if I need to, but it is very hard to put back metal if I get too aggressive.

I look forward to my next range session. Thanks again.

[SG4247]

Maybe you have checked this, but I have had many of this type of occurrence with new uppers.

Make sure the extractor has the o-ring installed on the spring. Fixed all of the uppers that gave me this problem.

You should struggle to move the extractor by hand when installed in the bolt, if the spring pressure is proper.

[Paul45LC]

Thanks, there was no o-ring. I'll have to see if can scare one up. Maybe my spare bolt for my 5.56 will have one I can borrow.

[Variable]

Not necessarily to poo poo o rings, but FWIW, none of my Grendel extractors are using them (nor builds I've done for others), and I've never had an issue without them. Only the occasional new build with the aforementioned extractor burrs/knfe edges. Once that's taken care of they run fine.

[rasp65]

I have never added o rings either but I did cut the ejector spring down a little and had no problems with extraction or ejection. This is the guide I followed on the bolt. http://www.snipershide.com/forum/ubb...Number=1943980 Here is the ejector mod: http://www.gswagner.com/arejector/arejector.html From what I have read the o ring is a #60 and it is supposed to increase the extractor force by 400%. Colt supposedly puts them on their M-4's. The rate of fire on my Grendel however is much lower than an M-4 it averages about 200 rounds per month.