My LR-308 is bummin me out

[General Disarray]

Last weak I took out my new DPMS LR-308 to break it in, and immediately was having failures ejecting spent rounds. Basically the rounds were getting ejected, but not exiting the chamber before the round below it was entering the chamber. Is this called a 'stovepipe' or something? Any ways, the round was log jamming with the next in line when it should have already exited the chamber.

I talked to DPMS and they said that the Rem Oil I was lubing with was too light for a gun that runs this hot, and the bolt was probably hanging up and not getting the round out fast enough. So I loaded it today with Tetra Gun Grease and had the same malfunction. A buddy suggested using Break-Free CLP. What do you all use? Has this happened to anyone else? :banghead:

 

[dutchy]

Dear General

(do you have a brother called Failure; and is he reading my harddisk?)


About your problem:
It one of 2 things:
A. The bolt does not travel far back enough to clear the empty shell or
B. The ejector does not work.

Possible causes:
A: insufficient gas pressure for cycling the action
A: a mechanical obstruction preventing full travel of the bolt
A: underloaded/faulty ammo

B: broken ejector spring
B: broken ejector

Get it to a competent gunsmith and have it checked out, 20 minute job.

Lubrication advice is equal to "I do not know, but do not want to say that"
Of course there are instances where lubrication is the problem, but statistically it falls into the category of highly improbable.

Hope this helps, and please give feedback.

 

[Big Az Al]

Isn't this similar to the FN FAL

If it is there is an adjustment, at the gas block, that by turning will restrict or relieve gas pressure, if not adjusted properly for the load being used it will cause either jamming or things to break!

 

[Zak Smith]

Check the ejector.

 

[tdperry30]

i had the same problem with my new lr308b with winchester ammo,switched to federal and problem stopped.just my 2 cents but the winchester seems to be light load .

 

[General Disarray]

Thanks all.

I wondered about the load not giving the bolt enough of a push, but I figured since it was factory American Eagle, they would be pretty consistent. Since they didn't do it every time I didn't figure that was it. I guess not. Thanks.

I know to 'check the extractor', but for what exactly. I just took it apart and scrubbed/lubed it. I hope it works better now with Break-Free CLP.

 

[Big Az Al]

Just another thought

Have you checked the screws, the two that hold the gas piston onto the bolt carrier, these being loose drove me distraction and ended up costing me money on one gun.

 

[Geno]

I too call the ejector, specifically the plunger hole. I had this happen with a Remington 700V...seriously!

The extractor would grab the round perfectly. However, the edge of the plunger hole had microscopic ridge on one side. It couldn't be seen with the eye, nor felt. Over a several rounds fired, the ridge shaved enough brass to clog the ejector to the point that it was too slowed-down to kick the round out. Remington had the gunsmith fix it for me. They simply smoothed the hole. It never failed again. I have seen similar with various types of rifles.

Hope you get it working. By the way, use M-Pro 7 oil, and perhaps some Moly (Bushmaster sells it. You need very little Moly).

Edit: Re: the screws, mine are driven into the bolt, and set with a punch. They can't come loose unless they break.


Doc2005

 

[Exposure]

I have seen two LR308's do this EXACT same thing.

In both instances the rifles were overgassed and needed adjustable gas blocks to run properly. Once the blocks were installed the rifles performed flawlessly with no brass damage and perfect ejection every time.

Take a look at the rim of the shell. Is it physically stretched where the extractor claw engages it, giving a bit of a "dip in the road" type of appearance? If so then your rifle is overgassed as well. I am starting to think that DPMS had a bad run of barrels with the gas port drilled oversize.

Essentially what is happening when the action is overgassed is that the bolt is attempting to open while the case is still swelled up tight to the chamber walls. The bolt begins to travel back with the extractor engaged, and it either

A. Dings the rim and is very hard on the extractor claw which will eventually break.
B. Rips the rim off the shell and leaves you with a case stuck in the chamber.

If your brass in not exhibiting these signs then ingore everything I just wrote!

Good luck.

 

[kirbythegunsmith]

Details

Here are some views to help determine the extractor mark situation.

This is a Remington 7400 with a unique mark, but not of a heavy force level.



This is a heavy force level pull deformity.


This is the rear view of the same case, with the extractor "pulling" area between the black lines, and the most deformity showing by the "IN".


Here is a side view of that rim.


Excessive case grip against the chamber wall or over-pressure shell, or excess gas flow (with excess bolt acceleration) can cause the rim edge to fail.


That should be enough to show the basic appearances of problems, at least enough to allow a shooter to make a diagnosis of these effects.

See my other posts.

[email protected]

 

[General Disarray]

UUUGGGHHH> I'm not used to leaving the range pissed off. It's usually a happy place for me. I've got 5 spent brass in front of me that did this failure today. I cleaned everything spotless and did a final lube with break-free CLP. 5 out of 50 is just 5 too many for me. It's American Eagle, BTW.

The brass all look like the second photo above from kirby. I'll try and get up a picture. Actually every piece of brass I collected has a groove from the extractor pressed into it. These 5 that failed to eject have deeper ones.

So I can see that kirby would call this a 'high level pull deformity', right? Can this be fixed without voiding my warranty? I don't want it out to DPMS for the remainder of the summer if I can fix it myself, ya know?

 

[Geno]

You know, when my DPMS AP4 .308 was NIB, I had to return it to the factory. Either the upper receiver (charging handle area), the charge handle itself, or both were improperly machined by 2/1,000ths of an inch. It functioned flawlessly, but it was chewing up the charge handle. The company allowed me to upgrade to a steel upper for about $117.00!!! Dang! Now, it is really sweet.

At this time, you need to call the company and get the involved. Take notes of the person's name who helps, what they say, and the promised date. Time slips away...uhuhmm. But, alas I digress.

 

[General Disarray]

I don't exactly know how to break down the ejector, but I've pushed on it and it moves. It's really tough to move, as is my extractor which makes me think they're okay. This hang up has been happening since the day I took it out. I still only have like 100 round down the pipe. From those I have maybe 10 of these failures. They are getting pulled from the chamber, but then aren't exiting the rifle, ya know? The extractor pulls them out of the chamber, but it's like the ejector doesn't flip it out. How do I get the ejector broke down to inspect it?