ORIGINAL: Pavomesa
According to my Speer manual you can use any sort of pistol bullet for the .44 mag. One of the problems with this cartridge is lack of real bullets designed for it.
Yep. The .444 is an odd duck. When first introduced, it was loaded with 240-grain, .44 Magnum pistol bullets launched at a much higher velocity than that for which they were designed. The results were often less than satisfactory, to say the least. Later, Hornady introduced their 265-grain .429" bullet, which I understand was designed specifically for the .444. However, even this bullet, (IMO), is a bit on the light side for something that is .429" in diameter. It is in the same category as the 300-grain .405 Winchester load-too light for the size game for which one would expect such a large-bore to be used! To be an elephant gun, the .405 needs a 400-grain bullet; so does the .444.
But, you can't use a 400-grain bullet with most .444's-they didn't make the twist (1-38"!!) fast enough! This is its' major shortcoming.
So my choice was the .45/70 instead of the .444. IF you have a .444 with a 1-38" twist, you are pretty much limited to bullets of no more than 300 grains or a little more. Blunt bullets could be a little heavier, like 320 grains or so. While the 240-grain pistol slug will work for broadside lung shots on deer, I would use a cast flatnose gascheck bullet of 300 to 320 grains for the bigger, heavier game if I had to shoot it with a .444. Even the 300-grain bullet only has a sectional density of .233, not much more than a 150-grain .30 caliber bullet (.225).