The first Marlin .44 mags were built on modified 336 actions years ago.
Not real satisfactory to use a 30-30 length action on a pistol cartridge and some of them didn't work so hot.
They have long since moved to the pistol length action of the 1894 for it and other pistol size cartridges.
Winchester did the same thing by using the Model 94 30-30 to make a .44 mag.
Again, the action is way longer then it needed to be, or should be.
Winchester went belly up before they really got around to bringing back a U.S. made 92 action for pistol calibers, except for the classy 92's made in Japan for Winchester & Browning.
A pitty too!
rc