Henry;
First, let me apologize. Since you admitted you had already blown up a gun and were still in the theoretically experimental stage, I was mildly astonished! There is no need to make .44 special cases if all you have are .44 maggies if the gun is a maggie. Your money would be better spent on different powders. For the large cases, you need to get away from the powders that are in the 3 and 4 grain range and go to powders that do a better job of filling the cases. There are powders that will give you .44 special velocities and pressures in .44 Mag cases. Unique is one of my favorites with a 240 grain cast lead, I can shoot 800fps easily. Accurate Arms #5 will give you a bit more velocity, around 1000fps, but still within the warmer .44 special realm.
Again, you didn't deserve my derision and I spoke out of turn. However, please, please understand you are dealing with hand grenades if you make a serious error.
Dan C