I am not familiar with the Mauser rifle. But here is my understanding of how the Carcano extractor engages with the cartridge. I am sure Walt will correct me if I am wrong.
The extractor engages the cartridge when the bolt is pushed forward and the very bottom portion of the bolt pushes the very top of the back of the cartridge forward until it clears the clip and is pushed up by the elevator into the receiver. Here are two of the cutaway frames that show this:

Here, the cartridge is being pushed forward by the bolt and the elevator is pushing the cartridge upwards such that the extractor engages the cartridge in the groove between the base of the cartridge and the body of the cartridge.

At this point in the forward motion of the bolt, the extractor is already engaged (into the groove between the base and the body of the cartridge). And if you were to stop the forward motion of the bolt at this point and pull it backwards, the cartridge would be pulled backwards also and ejected if pulled completely back to the fully open position. In other words, the bolt does not have to be rotated down to the locked position in order for the extractor to engage the cartridge (as you indicate is the case with the Mauser).
And Robert Frazier testified under oath that C-139 will (if the bolt is opened with minimal force) not throw the shell out with force, but will let it fall down at your feet.
This therefore is another anomaly that seems to negate LNs reason for Oswald loading one more round after firing the 3rd shot and carring the rifle to the the staircase because he might have to shoot someone who was inadvertently coming to the 6 th floors.
If the MC round was never loaded by operation of the bolt properly and locking the bolt fully seating the cartridge in the chamber after the 3rd shot, then it seems pointless for Oswald or other person to have carried the rifle across 180 ft of floor being in LOS of anyone who might come up the staircase, since the rifle could not have been immediately fired and would require pushing the bolt completely forward enough seat the cartridge snugly and the bolt handle rotated to lock the bolt so that the trigger mechanism would be engaged and the firing pin would work
He might simply have been smart enough to know that hiding the rifle would likely buy him more time to get out of town (before they found it and connected it to him). After he was arrested I think he was surprised how fast they were still able to do just that.
I am not familiar with the Mauser rifle. But here is my understanding of how the Carcano extractor engages with the cartridge. I am sure Walt will correct me if I am wrong.No other rifle should be used to attempt to verify the mechanical operation of the mannlicher carcano.
And I believe that you understand how the carcano operates , Charles..... Though you're not precisely correct in describing how the cartridge is chambered....
"the elevator is pushing the cartridge upwards such that the extractor engages the cartridge in the groove between the base of the cartridge and the body of the cartridge."the elevator is pushing the cartridge upwards (AND INTO THE ANNULAR SPACE ON THE FRONT OF THE BOLT ) such that the extractor engages the cartridge in the groove between the base of the cartridge and the body of the cartridge.
If the MC round was never loaded by operation of the bolt properly and locking the bolt fully seating the cartridge in the chamber after the 3rd shot, then it seems pointless for Oswald or other person to have carried the rifle across 180 ft of floor being in LOS of anyone who might come up the staircase, since the rifle could not have been immediately fired
pointless for Oswald or other person to have carried the rifle across 180 ft of floor being in LOS of anyone who might come up the staircase, since the rifle could not have been immediately firedYes, and this is just one of the indicators that reveal that the rifle was never at that sixth floor window...It was hidden beneath the boxes of books BEFORE the shooting.
He might simply have been smart enough to know that hiding the rifle would likely buy him more time to get out of town (before they found it and connected it to him). After he was arrested I think he was surprised how fast they were still able to do just that.Yes, Hiding the rifle would have bought him time ....and that was the plan, and it probably would have been hours or possible a day if the double crossers who played Lee for a sucker, by setting him up to be framed for murdering JFK....when they shot President Kennedy.
Lee thought that he was participating in a hoax in which it would appear that he had shot AT AT JFK.
And if JFK had not been killed there would have been no mad rush to find the killer. He hid that rifle before the motorcade arrived. If the cops had been looking for a person who had fired a gun as the president passed by....they wouldn't have been in a mad rush to find that person and his gun. But the killers foiled Lee's plan of fleeing to Cuba after the cops reported that someone had shot at JFK from the TSBD. They learned this after the spent shells, and the rifle were found by the employees who would have been working on the sixth floor that afternoon. Lee thought that he would have been in Mexico by
the time the shells and rifle were found.