Yeah - I miss my 1911.
Ported 5" Wilson bl.
260gr. Speer HP
2" 5-shot groups at 50 yards
from sand bags.
Seems to me the 300gr. FN's used 7.7gr. Blue Dot
for almost 800fps.
I would work up to those if I were you.
I got the 260g.r load from my old Speer manual.
The 30gr. Blue Dot load came from my ".45 Auto" magazines
published by Modern Day Periodicals in NY - annuals 1982,83 and 85.
I've never seen any others - what a wonderful treatise on the .45 Auto, though.