My bolt bit the dirt again!

triden

triden

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I don't get it. This is the second time in around 100 shots that my M305 bolt automatically disassembled itself. I posted a thread a couple months ago when it did this the first time.

Thread here: http://www.canadiangunnutz.com/forum/showthread.php/955591-My-bolt-just-bit-the-dust-*FIXED*

I ordered USGI parts and stuck them in my Norinco bolt, but same problem. Extractor came out and the rest of the bolt hardware scattered all over the ground in front of me. I don't get it. :confused:

Should I just bite the bullet and buy a new bolt? They are a little pricey and might not fit perfectly. What else can I do? I have no idea why this keeps happening to my M14.
 
So why didn't this happen last week? I'm down here in the monashee mtns. Could have brought a bolt or two down to try and fix your situation. Ahhhgggg. Next time I'll bring em down just in case. Sorry man.
 
Is the detent engaging firmly? Basically, everything interlocks, and if engagement is not secure, spontaneous disassembly is a possibility.
 
"...to my M14..." Start by remembering that an M305 isn't an M-14.
"...and stuck them in..." You fit 'em? Shouldn't really need fitting, but it is a Chinese rifle. I suspect the bolt may, I say again may be out of spec. A new bolt will require fitting for headspace. They are not drop in parts.
 
could be possibly the nose of the extractor touching the breechface and unlocking as the bolt closes I have seen this before on a gun that was out of spec
 
Check the bottom of the extractor stem, if it protrudes below the bottom of the bolt it might need to be ground down.
 
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you could put a little bit of dykem on the bolt and see where its rubbing ... that may help to see whats going on.. and if you work the action very slow just as it locks up, maybe you can see something different



Beater said:
could be possibly the nose of the extractor touching the breechface and unlocking as the bolt closes I have seen this before on a gun that was out of spec
Click to expand...
 
I agree with Beater"s comment regarding breech face contact.
There is actually a "National Match" modification to the extractor that could be applied here.
My guess will be either :
A) a weak extractor detent spring or bolt's extractor spring recess is too deep.
B) bolt/extractor hitting top of breech face as it goes into battery and pressure on extractor from case rim is popping the extractor off the detent.

I have had condition 'B' above arise in a few rifles now, both chinese and american cream of the crop rifles.
I would look for wear pattern on the bolt, on the "ring" that encompasses the forward outside end of the bolt.

Last thing, perhaps the actual bolt face has a deformation, machining error or brass deposit causing the base of the cartridge to not seat into the bolt face correctly, thus causing extra pressure on the extractor.
Ideally you should have someone with some real experience with these rifles have a look at it
 
bshooter said:
Check the bottom of the extractor stem, if it protrudes below the bottom of the bolt it might need to be ground down.
Click to expand...

You should check this, also use a USGI extractor and detent, but use either the USGI or Chinese detent and ejector springs, whichever seem to have the most tension.
 
You guys are a great help! I ordered a new USGI bolt kit (minus the bolt) and will put it together and check it all out closely. I tried to buy a fulton bolt from treelinem14, but they don't export them. I'm seriously considering a new bolt as the next step in fixing this if I can't get the new parts to stay in!
 
sunray said:
"...to my M14..." Start by remembering that an M305 isn't an M-14.
"...and stuck them in..." You fit 'em? Shouldn't really need fitting, but it is a Chinese rifle. I suspect the bolt may, I say again may be out of spec. A new bolt will require fitting for headspace. They are not drop in parts.
Click to expand...

Well my "M305" has M14s stamped right on the side, so..
When my Norc bolt disassembled itself, I took a chance and ordered a complete new Fulton Armoury bolt and headspace gauges. It slid right in and locked up tighter than the Norc bolt. It closed on both the Go and No Go gauges for .308, but did not close on the NATO 7.62 field gauge. As far I'm concerned that's good to go, it's within NATO specs. Shoots good too. The Norc bolt on the other hand swallowed the NATO field gauge effortlessly, kinda scary.
 
Mine just did the same thing last week. I've had about 350 rounds through mine. At the range, 2-3 mags in, I pull the trigger, nothing happens. Removed the mag, went to clear the chamber, and the extractor was gone. Like, gone, gone. I looked everywhere for the damn thing, couldn't find it. So I've got an order in with Treeline to ship me a new extractor, detent, and ejector spring and plunger. I'll give an update as to what shakes when I get her all back together and tested out.
 
I've purchased a bunch of spare trigger, bolt parts and roll pins for the M1A's and keep them in a nice clear plastic tackle box with dividers. Did the same with small AR15 parts too. The parts are cheap and good to have around.

Better to have it and not need it than to need it and not have it.
 
Usually the cause of bolt disassembly can be traced to the stem of the extractor protruding below the bottom of he bolt. The stem should be at a minimum flush with the bottom of the bolt or better still, a few thousandths short from the bottom.

Check to see if that is the situation. If so, grind or file off a few thousandths from the bottom of the stem until it fits flush or a little deeper from the bottom of the bolt.
 
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