Guys, been shooting a lot of cast bullets out of a 1911 since the mid 70's (averaging 2-3000 rounds a month until the mid 80's). If you need any help, happy to lend a hand as I can.
Since a lot of shooters went through the “Which powder is best” routine in the early days of IPSC (which really was practical shooting in those days). Unique, Bullseye 231 and a lot of powders were tried. Of all of these, the single most popular for years was 231. Problem with using Bullseye in a 1911 is gunk. We did try a lot of tricks to get better ignition, didn't work. End of last year I did shoot some ammo loaded with bullseye out of a new Shooting star magazine and found it was jamming because there was so much gunk in the mag. That's Bullseye, which is fine for wheelguns (and Ed does that one a LOT!) ;)
With the H&G#68 I normally use and are readily available if you can't cast. Some quick notes:
5” Gov't 16 to 18 lb. recoil spring. H&G 68 200 grain SWC. Any brass (except I don't load small primer pockets) 231 powder Federal primers (best and most consistent ignition even with service pistol like the 1911/1911A1 or a tricked out gun. Option is to use WInchester Large pistol. These are also good primer and the pressures of these two are consistent and proper.
Mild practice load for older guys, kids and women that aren't used to shooting a 1911 is: 4.7 to 5.0 grains of 231.
The old Hardball equivalent is 5.8 grains of 231 using the above.
The second powder option if your press can handle fine grained powder is titegroup. Currently popular with the some of the competitive shooters including 38 super. I can post loads for that also.
Over all length max is 1.260, you'll find that some chambers and magazines like the Para-Ord (at least the early ones) want it 1.250. With a slight jump to bore, these might not be as accurate in a 1911 made for 1.260.. but they still work fine. I've seen bullets seated shorter and they still work. Just be careful not TOO short!
Let me know if I can help.