LR308 failure to feed....

[hangunnr]

This rifle used to eat everything flawlessly. It sat in the safe for the better part of 2yrs until I got back with it recently. I've been experiencing this failure to go into battery with every load put through the gun, reloads and military ball.

I've throughly cleaned and properly lubed everything and tried new buffer springs and even one of the JP silent captured units. When it does cycle it will lock the bolt back after the last round so I don't believe I have a lack of gas issue but I'm willing to listen if you can point out why that might be a concern.

The cartridge enters the chamber about 80% or so and hangs up. The bolt is very difficult to retract when in this condition. When the bolt is racked the cartridge will freely enter the chamber. I've experienced this with multiple mags.

Any suggestions?

CR

 

[koden]

The round has not yet been forced back into the bolt and the extractor claw has not grabbed the rim of the case yet. To me it looks like something is interfering with the Bolt Carrier or the buffer. Maybe the buffer tube is tweaked? If the the round was stopping the BCG from moving forward I would think the rim of the case would have been forced past the extractor claw.

 

[BLDTYLRY]

Check gas tube alignment.

 

[ORD]

Check gas tube alignment.

^^ This! ^^

In addition, check to ensure that your carrier key hasn't come lose.

 

[bowslngr]

If you installed a Timney trigger, it could be the source of your problem.

 

[Pilky01]

I have had similar problems with certain ammo in my gap 10. It is a new rifle i chalked it up to break in. However when i examine the brass i can clearly see scratches where the case gets too thick. As I have continued to break in the rifle this issue is slowly resolving itself. The ammo i had problems with were either xm118lr with the 07 head-stamp the 08 runs great weird I know and some ammo i bought at wallyworld that was the only thing in stock called ZQI or something similar.

 

[hangunnr]

Tore the bolt down completely this morning and found the ejector retaining pin looking like this. I believe it was allowing the ejector to protrude out the bolt face too far.

Can I assume that pin isn't supposed to have that groove in it?

CR

 

[mtrmn]

No it is not supposed to have a groove---at least mine don't.

 

[Pilky01]

Mine doesn't have a groove either. It sure doesn't look like it is there on accident though.

 

[hlee]

I'm not sure i see how a problem with the ejector could cause the cartridge to hang up where it is. Perhaps not fully go into battery, but not hang up with over 1/2" of the cartridge sticking out.

 

[hangunnr]

Dosen't make a whole lot of sense to me either but we'll see when the new parts get here later this week.

 

[mtrmn]

If the ejector protrudes out of the bolt face too far, it will deflect the case sideways toward the ejection port just like you see in the pic. As the case feeds up from the bottom, it encounters the SIDE of the ejector instead of the END of the ejector. This causes the case to deflect sideways just enough to cause it to bind as the rear of the case will be trying to enter the chamber at an odd angle when the bolt comes up behind it. Since the case is against the SIDE of the ejector, it cannot correct itself fast enough before it binds. All this happens "before a cat can lick its ass."

 

[hangunnr]

Correcting the ejector cured the problem. She ran flawless this morning.

CR

 

[mtrmn]

excellent news!!!!

I would suggest buying at least a basic spare parts kit.

 

[Pilky01]

Glad you got it sorted. Nice job catching that one. I think I would have missed it.

 

[Bravo 1]

So the question is what caused the ejector retaining pin to have this grove ?

 

[LawnMM]

Gremlins

 

[problemchild]

Wow thats one for the books. IN 30 + years I have never seen that happen to an AR. Nice find......