The 444 Marlin was introduced in the mid- 60's to give their model 336 Levergun a boost in horsepower.  Over the years the .444 has been offered in a number of rifles and even a few pistols. It is another caliber that is seeing new life due to the changing game laws in many states allowing straightwall cartridges for deer hunting where they were previously limited to slug guns and muzzleloaders.