OK, I think I found the cause this time! There's a couple pins on the bolt that retains the thingy that hooks the extractor spring collar. Sorry I don't know the proper name but here's a picture showing the bolt with the pins partially out:
Here's a picture showing the bolt jammed by the pins hitting the guide (lifter has been removed):
And, here is a picture of the guide showing the pins hitting on the hinge edge of the guide. You can see evidence of the pins rubbing across the guide as the bolt moves.
Both pins have an opportunity to hit on the edge of the guide and jamming the gun. This explains why sometimes I could open the action about an 1/8" and other times a little more (the distance of the second pin). If the pins can make it past the abrupt edge of the guide hinge then they seem to do fine along the more gentle curves of the guide.
I have never removed these pins so I was surprised they drifted out. I assumed they were pressed in from the factory. Has anyone else noticed theirs drifting out on their own?
So how do I lock these pins in place? Ping them with a punch or get bigger pins? Is it common to have pins that drift on their own?
I'm beginning to see the light at the end of the tunnel:^)
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