Sticky bolt of the other kind.

[Tripodmvr]

When the fluting was done the whole bolt would have been dismantled. The bolt knob position is critical to the correct functioning of it in the action. If the collar unscrewed then the locking lugs to collar dimension will be off. I presume the thread is fairly fine?

[janfred]

That is definitely an aftermarket bolt. I can now understand how it could happen. And no, original RSA bolts are not threaded.

Good on you for fixing a professional's mistakes. Personally I'd try to get an original bolt. Might not look as tactical as that, but would be a lot safer in my opinion. Imagine the locktight gives again and allows the collar to rotate far enough without the locking lugs locking. I don't think that handle is strong enough to act as a bolt lug. Your idea of pinning it seems prudent.

[big5ifty]

Those pictures look like a screwed on collar.

There is a definite undercut visible in the second picture, where the body of the bolt in is the collar, the collar overhangs the bolt body about half a thread.

If it was one piece, there would be no undercut, it would be flush, with no demarcation. It's highly unlikely that the the undercut was machined into a one-piece bolt.

If you remove the firing pin and look in, you'll clearly see if the body is threaded in or not.

No need to fix what isn't broken.

From a design point of view, these rifle bolts were probably made as economically as possible. Much cheaper to assemble a rifle bolt from screwed together bits than machine it from a solid block.

From a stuck bolt perspective, if you have a fired case stuck in the chamber and the collar unscrews on open, there is no way to open the bolt. The barrel will have to be removed, the case extracted, and the bolt lugs mechanically engaged and rotated out.

[big5ifty]

I presume the thread is fairly fine?

It is a fine thread, I didn't measure what it is.

[janfred]

You must have better eyes than me. I took the bolt apart as much as I could and could find no evidence of a seam or thread inside or outside. Did the same with the bolt from my other rifle. There are plenty machining marks though. As far as I am aware the bolt body and handle is a single casting or forging machined to size, just like the receiver. Even the modern Musgrave M21 bolts are all one piece as per their website.

Due to machining tolerances of the day, RSA bolts are not always interchangeable. Most knowledgeable gunsmiths when faced with a RSA action would true the action before fitting a barrel; i.e. chase the thread, square the front and lap the bolt lugs.

Something else you may need to check. If you couldn't close the bolt, it is reasonable to suspect that the gunsmith didn't either. So, to my mind, the headspace is suspect. The bolt lugs may need lapping as well to ensure proper bolt lug contact.