Posted: 7/23/2017 11:47:20 AM EST
My most recent build is giving me fits.
The bolt locks shut. And I mean LOCKS.
I have to use a mallet to get it to unlock.
It locked up the first time I fired it. It locks up when cycled with a dummy round.
I changed out the bolt with another rifle. Still locks up.
Did you change the bolt or bolt carrier? Have you checked your gas tube alignment and your barrel extension? Pics would help
Changed both the bolt and carrier.
I'll pull the gas tube assembly to rule that out.
Thanks for the ideas.
What brand bolt?
Is the cam pin hitting the upper receiver?
Pics of the bolt face and lugs.
Pics of feed ramp alignment. Can indicate a barrel extension pin which is not clocked properly.
You say that the action locks up when fired or when a dummy round is chambered...
Does the action lock up if the bolt is closed on an empty chamber?
The dummy round that you tried. Did you make it from a fired round or did you use a commercial made dummy round (plastic or metal)? Did you full length resize the casing before inserting the bullet. A round fired from a different gun has expanded to fill the chamber of the gun it was fired in (which is not the same size as your gun). Odds are that if a casing is not resized, it will jam when inserted into a different gun.
A similar problem was a small piece of brass on the forward side of the locking lug. Younger eyes and a pick solved the problem.
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