Welcome to the forum and thanks for asking our advice
Kalen, I am glad you stuck around. This forum is one of the better ones and a few impatient/intolerant folks can be found anywhere. Forgive them. They are more concerned with safety (yours) than decorum.
Unique is an EXCELLENT powder for light to medium loads. I have used it for 35 years. It is a little sooty, but cleanup is part of the fun, right? My best girl dabs on a little Hoppe's #9 when she is feeling frisky.
(kidding)
Every powder has its niche. The niche for H110 and Winchester 296 (the same powder) is maximum powder loads. It needs the highest pressure to reach the proper burning pressure and temperature for predictable, stable burning. A light bullet does not provide enough resistance for that. A light crimp does not, either. A smallish case does not allow for a good, long burn time (though if you match case volume, bullet weight and charge weight you could do it in a 44 Special case, I'll wager).
However, I will not wager my own money or my own body parts or gun. A 44 Special case fired out of a 44 Magnum gun if loaded with a safe combination of H110 and bullet can be safe because the gun can contain the pressure. But if that cartridge is loaded into a 44 Special gun there will probably be more pressure than the gun can stand. And a case loaded with H110 to 44 Special pressure levels cannot be depended on to avoid erratic behavior (incomplete burn, stuck bullets, pressure spikes and such other dangers). Tom Matiska is right. Slow powders need to "get going" to burn right. In H110's case, this is especially true.
I mentioned finding a safe load for firing a 44 Special case in a 44 Magnum gun as an example. To find such a load, you would need to equip a ballistics lab and run the experiments (or find a lab that did and was willing to share the data with you). Neither is worth the trouble, since you have a 44 Magnum gun and 44 Magnum cases are readily available (even if more expensive in your locale). Older manuals with 44 Special recipes were using the powder that was available AT THE TIME OF PUBLICATION. And using ballistics equipment available at the time, too. Powders have changed a little bit and ballistics science and equipment have become more sophisticated, too. By all means, if you have 20 year old powder, check a 20 year old manual. But also check a current manual as well. Safety always, safety all ways.
Frankly, I nave never owned a single piece of 44 Special brass, though most of my shooting is 44 Special power levels. And when I find any 38 Special brass, I give them to my friend who reloads 38 and .357. Most of my .357 guns have never even SEEN a 38 Special case, and none since 1976. Keeping only one chambering of brass keeps my supply logistics simpler. I never worry about separating 38s from 357s or 44 Special fron 44 Mags.
The respondent who suggested 44 magnum brass (sorry, I cannot find your name right now as I type this) is spot-on. I would go so far as to trade my 44 Special brass for 44 Mag, or powder or primers. But that's just me. Others find it more convenient to know that Special cases have special power levels and Mags have Mag levels. Me, I have to read the labels I put in the boxes to know if my loaded Mag brass has Special energy levels or Magnum energy levels. So, do what you prefer.
Lost Sheep