2007 M14, FAIL TO FIRE PROBLEM, AGAIN!!! & UPDATED with Pic! (first post)

I'm willing to bet that the chamber is sooo loose that the round is rattling around in there. Had a rifle that did the same thing 2 weekends ago. The bolt lugs were loose and it swallowed all of my chamber gauges. Swapped out a different chinese bolt, tightened it up a lot and it spec'd out at 1.638"....fired every round we fed it.

Originally I thought it was a weak hammer spring as well so I swapped out my trigger group and it did the same thing. Measured the chamber and holy cow!

But hey what do I know :rolleyes:
 
Oldsmobiler said:
I'm willing to bet that the chamber is sooo loose that the round is rattling around in there.
Click to expand...

I have fired cases... But can't "mike 'em"... Gonna have to put that piece of kit on the must have list... Oh, & none of the fired Federal cases were split or showed any signs that something might be wrong...

Cheers
Jay
 
Personally, I know nothing about M-14's, but I think that Oldsmobiler may be on to something.

Look at the picture of your fired Federal rounds. It looks as though the primers are backing out quite a bit, no? (I can't really tell from the angle of the shot.) While the primers in the Portuguese surplus look to be seated deeper.

Jay said:
photo-332.JPG
Click to expand...

If you have loose headspace the primers will back out. I had it happen with an old Model 94 I had years ago, and it improved dramatically when I exchanged the bolt.

That may be another avenue to explore.

Del Selin taught me a trick on how to check your headspace back then. You tape a piece of masking tape over the base of the cartridge (trimmed to fit) and then try closing the action.

After each attempt, you keep adding layers of tape to the cartridge base until the action won't close properly.

IIRC, the action closing on one layer of tape was acceptable, two layers was still acceptable but pushing it, and three layers of tape was excessive (at least on a Win Model 94.)

By swapping my bolt out, I went from the action still closing easily on three layers of tape, to being tight on two.

I don't know how that would translate to the M-14, but you might want to give him a call and ask. He was really helpful getting my Model 94 turned into a safe shooter again.

BTW, there is nothing like a thorough disassembly and cleaning of the bolt, to get rid of ALL the grease and crud that may reside within.


For those uncertain of what masking tape is:
MaskingTape.jpg
 
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Jay the best thing to do now is to start fresh and check the chamber. I will guarantee that its pretty loose. The other thing you need to realize is that the fired case in an M14 is still growing as its being yarded out of the chamber. I did this test last weekend as well. I turned off the gas assy and fired a round (you have to rack the op rod to extract the empty case). Next I fired the rifle in normal fashion. The cases varied by about .003 to .002" and as much as .005"

See if there is someone in your area that can do the work for you and check over the rifle. Its an easy fix if you have the tools and a spare bolt. I had a few spares on hand and it took them all to find the one that worked best.
 
A little update... I spoke with Marstar & they have agreed to take a look at the rifle at no cost to me. I've always had excellent service from them & hope that they can solve this problem for me...

I'm also sending off 3 cases to our guru Hungry to have him mike 'em & see if that might be the problem...

I'll update again when I know more. Thanks for all the input guys, greatly appreciated!

Cheers
Jay
 
This rifle didn't sit in a Gunsafe for a year or more cocked?

The weakest striking .308 I have ever owned was a BLR 81 and it went the deepest to my knowledge in Federal primers, blue box ammo and some 210s i used to try handloading with 4064.
 
M14's are designed to have relatively loose headspace and it generally will not prevent a rifle from firing. Sadly, it is difficult to diagnose a problem like this over the internet.

Were the Portugese rounds reloads? Maybe you're squeezing them too small?

Has the hammer spring got lots of life in it?

Is there thick grease on the hammer spring?

It could also be that the firing pin protrusion is below spec - a new firing pin or bolt would fix that if it's the case.
 
Claven2 said:
M14's are designed to have relatively loose headspace and it generally will not prevent a rifle from firing. Sadly, it is difficult to diagnose a problem like this over the internet.

Were the Portugese rounds reloads? Maybe you're squeezing them too small?

Has the hammer spring got lots of life in it?

Is there thick grease on the hammer spring?

It could also be that the firing pin protrusion is below spec - a new firing pin or bolt would fix that if it's the case.
Click to expand...

I'm going to send fired cases to Hungry to see what they 'mike out' to be...

The Portugese ammo is right outta the crate, & 200 round battle packs, factory 'fresh', not reloads.

The hammer spring 'seems' to have lots of life... It fired the Federal factory stuff...

I agree, it could be the firing pin...

We'll see what Marstar does with it WHEN I can get it to them! Dang Postal Strike!!!

Cheers
Jay
 
Update... Rifle was dropped off to Marstar yesterday, got the call today that it is fixed. They replaced the hammer spring in the trigger group & it now fires Winchester White Box 7.62x51 ammo, closest Marstar had to the Portugese NATO ball it had troubles with...

Will report back again on Friday IF there is a problem at the range... Here's hoping it's gtg...

Cheers
Jay
 
Jay said:
Update... Rifle was dropped off to Marstar yesterday, got the call today that it is fixed. They replaced the hammer spring in the trigger group & it now fires Winchester White Box 7.62x51 ammo, closest Marstar had to the Portugese NATO ball it had troubles with...

Will report back again on Friday IF there is a problem at the range... Here's hoping it's gtg...

Cheers
Jay
Click to expand...
WoW!
I might have just tuted my own horn.
Satain said:
Try a granad hammer spring.
Click to expand...
;)
 
The hammer will hit harder but I bet the chamber is still sloppy. Next trip to the range take five rounds of Port and turn off the gas valve. Fire the five rounds and manually rack the op rod and be careful not to let the empty cases bounce off the ground. That will give you the EXACT size of the chamber you have. If Barney is busy shoot me the cases and I'll do it for you...if you throw in a new round as well I can mike that to let you know the difference
 
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