M14 Forum

akjaeger · February 10th, 2012, 04:48 PM

I have an LRB M-25 that gets empty cases jammed between the top of the bolt and the scope rail, not allowing the next round to fully chamber.
I think the cases are ricocheting off of the windage knob of the scope.
Any way the scope knob has brass streaks on the bottom of it.
How would you tune the extractor to fix this?

colder · February 10th, 2012, 04:55 PM

Are you're ring bolts facin towards the ejection side? If so flip them around. It's a start

akjaeger · February 10th, 2012, 04:57 PM

Thanks colder, but no they're facing the other way.
I've tried to unclutter the ejection port as much as possible, it still jams up.

colder · February 10th, 2012, 04:58 PM

Is it a LRB bolt or USGI bolt?

SmokyBaer · February 10th, 2012, 05:05 PM

Fwiw... my Scout really started flinging the brass after I cleaned and lubed the extractor, ejector and spring. Surprisingly, Springfield Armory did not lube any of the bolt parts. Really made a difference and maybe that'll help on your LRB.

colder · February 10th, 2012, 05:11 PM

Try this search LRB M25 - Brass ejecting into scope housing

colder · February 10th, 2012, 05:22 PM

I did it again, sorry for highjacking the thread again!

akjaeger · February 10th, 2012, 07:32 PM

LRB bolt

Gus Fisher · February 10th, 2012, 08:14 PM

Akjaeger,

You don't modify the extractor to try to change direction of the ejected brass, but sometimes changing the length of the ejector springs or the shape of the ejector can on a very few occasions - cause a slightly different ejection pattern.

What I would try first after all else failed would be to: 1. First buy a new ejector spring in case I screwed up the current one and 2. clip a coil or off the eject spring at a time until it worked (or not). I have never been a fan of grinding a different angle on the ejector, though, as it would cut through the surface hardness and even if you lucked out with a better ejection pattern for a while, modified ejectors soon wore out.

82nd ABN · February 10th, 2012, 08:24 PM

check with a member yellowthunder, he just went through some thing like this as well. He wound up modifying the spring like Gus mentioned ask him what his results were.

akjaeger · February 11th, 2012, 04:56 AM

Thanks guys!
I'll let you know what works.

art7 · February 11th, 2012, 08:42 AM

Gus is right there with the base principle: modify the cheapest part first ....

In addition to cutting off coils to make the spring weaker, you might also try dropping a small shim of sorts down the hole, to over compress the spring slightly and increase pressure. Obviously, make sure your shim is slightly smaller in diameter than the 0.125 spring hole, so you can get it back out, and also make sure it does not overcompress so far that the spring stacks solid with the ejector standing proud of the bolt face .... Another option is getting a longer spring to increase the pressure. 0.12" OD springs are a very common size, so if you go to eg McMaster-Carr, you can get lots of options for wire size, length, etc.

Mongo · February 11th, 2012, 08:49 AM

Any predictions on how an adjustable gas plug (set to vent more gas thus slowing the cycle) would affect this problem?

akjaeger · February 15th, 2012, 09:07 PM

I ran 60 rounds through the LRB today, no hiccups. Tried Milsurp and my hand loads.

I took the bolt apart, cut a coil off the spring lubed everything up.
I also moved my front scope mount to the forward slot in the LRB base. The corner of the forward mount was sticking 1/8" into the ejection port, but there were no brass marks on it.
The Leupold 2.5X8 MK4 I'm using doesn't really have enough tube length for this rifle. I'd like to set the scope back a little more.
Thanks to everybody for the info.