Posts: 497
Threads: 41
Joined: Aug 2013
I've had good luck with Olympic arms 7.62x39 bolt. Same as in my photos.
Out of stock currently, but due in any day:
http://www.midwayusa.com/product/798650/...39mm-matte
One fellow in the club has 3000 rounds on this same bolt/extractor in his early Grendel using a compressed load of N540 and the 107 Sierra MK!
I keep thinking his bolt will crater any day, but never does.
Posts: 93
Threads: 3
Joined: Sep 2014
IMO looking at your fired brass your chamber may be a little rough. It will smooth out over time. That combined with the rounded edge on your extractor is causing your issues. I had an extractor like that and took a dremel to it and squared off the radius and my FTE issues went away. I then replaced the extractor with a quality one (cant remember where I got it though, probably my lgs). Replace your extractor and you will probably be fine.
Posts: 8,507
Threads: 241
Joined: Sep 2014
The best bolt with a .125" face depth is the LMT enhanced, hands down. It's made from an AerMet alloy, and guys who have broken every 7.62x39 aftermarket bolt out there have not been able to break the LMT. One guy who is renowned for breaking everything 7.62x39 in full auto mag dumps, was able to break the extractor lip off, which is the most common failure point on aftermarket 7.62x39 bolts, followed by lug shear.
7.62x39 has a lot of bolt thrust, because of the extreme case taper, so it can be really hard on bolts, even with significantly lower working pressure than 5.56 NATO.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
Posts: 14
Threads: 1
Joined: Feb 2015
Ended up getting an Olympic Arms bolt from Midway that came in today. I noticed a big difference in the extractor as it looks like SG4247's extractor. I didn't remove the extractor from the bolt assembly but noticed that it is also a lot stiffer than the Underground Tactical bolt I was running. I'm thinking that may have been part of the issue as well. I'll know by this weekend if my problem is solved though.
Thanks again everyone for the help.
Posts: 6,206
Threads: 50
Joined: Mar 2011
If the chamber is rough I'd consider polishing the chamber with Flitz. I do this on my 22 rimfire chambers and it really helps. I can't see it hurting anything on a centerfire chamber. I use a barrel mop with flitz attached to a cleaning rod. I attach the rod to a electric variable speed drill and am careful not to get into the rifling. A 20 gauge shot gun mop or 30 caliber mop might work pretty good on a 6.5 Grendel chamber.
Posts: 1
Threads: 0
Joined: Feb 2016
So what was the verdict with the new bolt? I am having a similar issue with a BHW 20" barrel/bolt and am pretty sure is extractor issue. Been through most of the checks outlined in thread so was curious if your new bolt/extractor resolved problem for you.
Posts: 14
Threads: 1
Joined: Feb 2015
Shot 20 rounds saturday with the new bolt and didn't have any issues at all. This seemed to have fixed the problem.
