In a thread in the custom rifle forum comparing the Win 70 and Dakota 76 actions a member noted that on early Dakotas you could manually rotate the bolt shroud when the bolt was open.

I decide to check some of my rifles.
Win 70 - has a lock, can't rotate it.
Mauser with after market 3-position safety - Can rotate.
Mauser with military shroud - cannot rotate,
Kimber Montana - can rotate.

What about other actions, Rem 700, Ruger Hawkeye, CZ 550, Sako, Tikka, Bergara etc.

It seems like the lock should be a standard feature on any bolt action.

quote:

Mauser with after market 3-position safety - Can rotate.

must not be installed correctly

every 2 and 3 position low scope safety on a Mauser 98 will lock the shroud.

Unless you leave out the spring and lock, which is easy to do and some like them that way.
Few bolt actions did not lock the bolt, but now it seems derigeur to do so.
Why do you need a lock at all on a bolt action? No other type of action has one; i.e., you can open the action any time you want to.
It is a military feature. Some argue that they want to un load them with the safety on, (like the three position Model 70 types do).

Wait! Just actually read your post; you mean a bolt shroud lock, and the ability to rotate the bolt shroud with the bolt OPEN.
Sure, again, that is a military feature; Early Mausers do not have a bolt shroud lock, The 1917 Enfield did not. The 98 Mauser did.
Model 70 Winchesters did; Remington 700 series do not.
What to know when you need it and when you don't?
You need it when you have a three position safety that retracts the cocking piece but does not lock the bolt to the receiver, so you can open the bolt with the safety on. If you did not have a bolt shroud lock, your shroud would rotate when the bolt was open and then your rifle would not work unless you manually screwed it in the right position; not a good thing.
Now, on a Rem 700, or Enfield, for example, the cocking piece sits into a notch in the bolt rear face, keeping the shroud from turning when the bolt is open.
That's when and why.

And on a 98 Mauser, it does not matter what kind of safety you have,; original or aftermarket, the bolt shroud will lock. Even the commercial ones that do not have a safety in the shroud, retained the lock.

On the kimber with the bolt open it's pretty easy to rotate the shroud on purpose. I don't know how it could happen on accident.
You can't rotate the win 70 shroud on purpose.

Send me a picture of your bolt shroud, left side, unscrewed from the bolt.
What position is your safety in whilst you are turning the bolt shroud.

I think we have determined that the Kimber has no positive bolt shroud lock and uses a detent ball to locate the shroud when the safety is in the mid position.
As long as you don't try to turn it when the bolt is open, it should work.
I have never worked on one though, so this is an opinion, which I hate.