Is that a model 91/38 Manlicher carcano that the man is using? It looks like a M91 Calvalry carbine....and the cartridge he holds up to the camera sure as hell is American made ammo ..which uses a projectile that is smaller than the bullet that the rife was designed to use. Thus the bullet can move around in the chamber which allows the bolt to cam over the rim of the cartridge. AND we have no way of knowing if the carbine is badly worn......
Always amazed at how little you know. The assassination was carried out with American made ammunition. WCC lot 6000 is American made ammo. WCC=Western Cartridge Company.
I doubt you know this but It is the same receiver just a shorter barrel. I thought you said you owned some of these rifles? Do you actually believe the chamber is made so sloppy that the shell casing can freely move around in the chamber?
The inability to place a shell in the chamber and close the bolt sounds more like a lack of strength issue. Simply put you are unable to muster the arm strength to make the extractor spring apart. I was thinking you are an average adult male but maybe I need to rethink that. First unable to reassemble a few screws on the carcano in a minor amount of time and now can't single load a carcano by dropping the cartridge in the chamber and closing the bolt.