I've used #2 in both the .44 mag and .45 Colt. No problems. My loads are in the 1,000 fps range, because I wanted to regulate the point of impact at 25 yards with some hunting loads, and that's the velocity that I needed. Below that velocity level, I did not get real consistent ignition. Didn't chronograph the loads but I could sometimes tell a noticeable difference in recoil. Once I got over 7 grains it seemed pretty consistent.
In the .44 I use a 240gr. SWC, and in the .45 Colt I use a 255gr. SWC. In both cases the powder charge is about the same, between 7.5 and 8.0 grains, I forget exactly what the measure is set on. Note - this powder charge doesn't appear in the AA manual for the .45 Colt. It is surely over pressure for Colt SAA's and the like. But in my Blackhawks it is just fine. 6 shots generally go into 2 inches or a little better at 25 yards. I don't claim to be any great shot, though.
I also seat the bullet so that the case crimps on the shoulder to cut down on the airspace. Again - something that you won't find recommeded in the manuals, as it raises pressures. But I am staying well away from any sort of max loading. The cases come out of the chamber really, really clean this way. Standard primers by the way - Rem. 2 1/2's if memory serves.
This load is fun in the .44 especially for shooting gallon jugs filled with water - at 100 yards. If sighted in about 3 inches high at 25 yards, it hits right on top of the front sight at 100. I've also used it to shoot big rocks at double and triple this distance. Of course you need some elevation for that. But the long-range accuracy is pretty good, and the recoil doesn't beat you up.
You can sometimes find that powder sold as surplus at www.gibrass.com - that's where I got mine. It's listed as #102. Apparently this was a cannister lot of #2 improved. I got 6 lbs for เ, plus a few bucks for shipping. A friend was buying several large cans of surplus powder for his .50 BMG so we split up the shipping costs.
Give it a try... I think you'll find it very useful.