@Sidetrack Yes pretty much, I have found a picture from an old MKII manual below (which is the same principle slightly different execution), the bolt body is cut with helical grooves that align with grooves in the bolt sleeve to cause the rotation. There are 7 locking lugs which make it quite a strong action.
I know it has been mentioned on here before on an old post of mine, re the safety issue off assembling the bolt incorrectly. I have taken mine apart several times, and have failed to assemble it incorrectly in a way it will both fit into the rifle and fire. I have no doubt it could happen, especially in a hurry, and of course I am doing it with the hindsight of knowing it can be done wrong but it generally seems safe to me.
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