As was posted, the .44 Henry was basically similar dimensions to the S&W 44/100 (as it was first called), aka .44 American. Both used heel bullets, and the case was approximately the dimensions of a modern .41 Magnum. As the external dimension at the mouth was about the same as the bullet diameter, this required the use of a "heel" bullet. (The .22 rf uses a heel bullet, BTW.) Heel bullet ammo is not the easiest to load, as a crimp is a PIA to accomplish. The Russians apparently thought about the same thing, and asked S&W to modify the .44 American cartridge to use a straight shank inside-lubed bullet. This became known as the .44 Russian. With the advent of smokeless powder, the .44 Russian was lengthened to prevent use in older arms, and this became the .44 Special. That cartridge was lengthened once more when the loads went bananas, to become the .44 Magnum. I doubt any manufacturer would want to chance a toggle-link action with the .44 Magnum (we sometimes can it ".44 Extra Long Russian), and .44 Russian would be a limited sale item. So I would guess if anyone wanted to put out a Henry in .44 CF, it would be the .44 Special. The same has been done for the '66, or so I understand.