Failure to extract shell

I <3 M14

I <3 M14

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What would cause my m14 to not extract the spent shell casing?
If i manually cycle the op rod it works no problem... but when i fire a round the shell is not extracted, causing it to jam once it grabs the next round. Any ideas?
Dirty chamber, problem with the extractor?

Thanks.
 
problems

I <3 M14 said:
What would cause my m14 to not extract the spent shell casing?
If i manually cycle the op rod it works no problem... but when i fire a round the shell is not extracted, causing it to jam once it grabs the next round. Any ideas?
Dirty chamber, problem with the extractor?

Thanks.
Click to expand...

There is a difference between extraction and ejection. You say the rifle jams once it grabs the next round.

1. Does the empty shell partly come back into the receiver opening?

2. If it grabs the next round, is the empty partly still in the chamber?

3. What ammunition are you using....make, grain weight, etc.? Reloads or Factory ammo?

4. Has the rifle acted up like this before?

The M-14 gas system needs a certain pressure to operate it. While it is quite flexible in what it digests, a light loaded reload, a load with a lighter weight bullet, or improper powder will create a short stroke in the system.

If the cartridge case stays in the chamber, then it is an extraction problem. If it comes back a bit and jams, with some of the cartridge case exposed, then it is an ejection problem.

A slower burning powder will create a condition that will not give enough pressure to operate the system. The pressure has to peak at the right place in the barrel. A worn gas piston can allow too much gas to blow by it, and not operate the system.

On some models of firearms, there is a relief valve to vent extra pressure out so that the gas system does not get bent up, and some have a way to cut the gas system off completely, generally for launching grenades.

That should give you a start.
 
Yup, it's a failure to extract problem. As in shell stays in the chamber after firing. It's a new rifle... 100 rounds flawless then this problem everytime.

I cleaned out the chamber really well, and am going to try different ammo (was using IVI surplus) and see if that works. Otherwise may try changing out extractor and spring.

Thanks
 
Check to see the extractor detent if it's still in 1 piece. Also witch bolt make is this occuring on & has the ejector\extractor springs ever been cut?
 
bolt is a TRW with GI (?) internals. As far as I know, springs have not been cut. Also looks like extractor is still in one piece.
 
I <3 M14 said:
Yup, checked that. It's feeding fine, it's just not extracting the spent shell.
Click to expand...
K let's review what you have done.
Checked the bolt for any damage.
Checked the op-rod for any bur's or machine marks that might off set the spring.
Checked the gas assembely to see if it is lined up to the whole and the gas port is opened.
Then I am out of idea's. Maybe try some JB Bore bright for the chamber. Other than that see if you can attend a Hungry clinic as M14Doctor won't be up for atleast another week as he is waiting for internet to be hooked up to his house.
 
Nothing looks damaged/broken. I'll re-tightening everything and I already cleaned the chamber. Will try to get out and test it tonight and see what happens.
 
What barrel is on the rifle? Is it NM with a tightly cut match chamber?
If so it may just need a really good cleaning/polishing. You did say it fired 100 rounds no problem before this and the extractor looks fine so that has me thinking buildup in the chamber. If its a usgi barrel this is unlikely. They have larger chamber tolerances.
 
Inspect your gas plug and gas cylinder....the operating system is not only sensitive to gas pressure (as lots of folks have mentionned) but also a very specific gas volume. As the gas system fouls, carbon and other cr*p deposit on the internal surfaces of both the gas plug and the gas piston such that their internal volume can be significantly reduced. When this happens, there is not enough expanding gas to properly actuate the action of the gun, essentially causing it to short stroke.

The internal volume of the gas plug is relatively easy to maintain - all you need to do is use an appropriately sized drill bit to ream out the carbon bits. Stop twisting when you feel steel.

The internal volume of the gas piston is slightly more difficult to clean as there is an internal step down from the main body of the gas piston into the shank (the part that protrudes from the gas cylinder...yes it is also hollow). Sadlak makes special drill bits with handles for this specific maintenance item.

The point above on checking your gas plug tightness is also a good one....they can work themselves loose over time, bleeding gas that then does no work on cycling the action.

Lots of folks have also suggested the extractor as the possible culprit. If it works ok when hand cycling it would seem to me it's grabbing the rim of the case ok. I would suggest checking/cleaning your gas system before trying to diagnose a faulty extractor, especially if it was working ok before and still extracts when hand working the action.

The M1A/M14 type rifle does have a very quick acting gas system...Glen Zediker in his excellent article titled "Match Loading for the M14" describes the action as quick enough that the extractor/bolt/operating rod is travelling backwards before the brass has relaxed/shrunk from the pressure of firing. Any burrs in the chamber could cause the case to stick a bit. With a little bit of carbon buildup in the piston/gas plug the combination could cause the action to short stroke earlier than it would with just one of these problems.

Good luck, hope you get your gun running again.

Brobee
 
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