Hello Mikey,
It is the .450 Marlin for which the most recent Winchester Model 94 Timber Carbine is chambered according to the Winchester web site. A just asked a dealer about it and he says it is the .450 marlin and that they are currently available from distributors. Assuming that the information is true, this could be a North American big game hunter's dream. It should be able to take anything from whitetail to the largest Brown bear! I wonder if anyone makes true heavy weight bullets for the .450? Garret and Buffalo Bore have loaded large bullets for the .45-70 for several years.
Kindest regards,
Levergunlover