The Acme bullets and RCBS Cowboy dies work very well. That's what I use. My powder is SR 7625. Can't remember exactly why I have it but's perfect for 32 Long. It has about the same burn rate as Unique but meters a lot better.
I bought several cans of 7625 about 15 years ago to use in my 25-20 cal 1892 Winchesters. I have only used 1 can and haven’t opened another one yet. As soon as I use up the last of my 25-20 I will do another run. This powder has worked well in the 25-20.
I started reloading in 1972 with .38 Special loaded with 148 gr WC and a midrange charge of Bullseye . Later came .45 ACP and AR, 44 Mag , 30 Carbine and a whole lot more.
I do see 7625 listed in published data for .32L. The 2 most important característics are even metering and thorough combustion in 2”-3” barrels. W231 meters well and burns clean. AA5 was ok but I am saving this for .38 Spl & .38 S&W.
While the powder situation around here has improved there are certain powders that still have not shown up. Our LGS has recently received AA5 , AA2, Titegroup, W244 and IMR 4227. This covers my Bullseye, Unique and 2400 applications.
I am really great full for the level of support that RCBS has provided to those of us who are trying to keep older calibers alive.
Except for .351 SL, .38 S&W and 25-20 all of my dies are RCBS. While I have a few Lee molds the rest is a nearly even split between RCBS and Lyman.
Another caliber that I am working with is .38 SW. I am ready to start a run of 500 of these with the Missouri Bullet Co 146 gr RN.