I only load pistol in 44 Mag and 9mm right now. Partly due to availability and partly because I already had it I settled on Red Dot for lower end 9mm loads and Longshot for higher velocity stuff.
LongShot can also reach respectable velocity in the 44 Mag with the 240 grain bullets.
I've been looking for Unique, but have yet to find any. Back when I used to shoot 357 Mag and 44Mag a bunch I used a lot of Blue Dot and Win 296
If anyone is interested TargetSportsUSA has Winchester small pistol primers in stock.
I load and shoot a lot of 32 cal, 380 and 9mm mostly for target/plinking fun. Use Clays, 700X, Titewad, and Titegroup for those. Getting up into the 10mm, 357, 44 and 500, I use a lot of Blue-Dot, Longshot, H110 and 2400.
I did some experimenting a couple years ago working with the 45GAP. It has pretty limited data in reloading Manuals. I rounded up samples of pretty much every non-magnum shotgun and handgun powder that I could locate. I worked with: Titegroup AA#2 AM Select Unique 700X True Blue Universal 231 HP 38 800X Longshot WST WSF CFE Pistol BE 86 ZIP Solo 1000 Green Dot E3 Clays Red Dot HS6 20/28 Power Pistol AA#5
I was not all that impressed with HS6 or 800X, however I got satisfactory results with pretty much everything else.
I probably use more H110 in the 357 Maximum, 44 Magnum and 480 Ruger that any other powder. I have no issues with AA#9 or 300 MP either. I could live with any of the three and be completely happy.
Loading 38 Special, 45acp, and 45GAP I probably use more American Select than any other powder today. I got to using American Select when Unique got hard to find. I could live with pretty much all of the powders on the list above if needed. I mainly load lead bullets, with moderate loads.
