Historically speaking, there have been several different .45 Colt b.p. loadings in boxer primed cases over the years.
.........28 grs., 35 grs., 38 grs., 40 grs.
Awhile back I purchased some U.M.C. headstamped .45 Colt b.p. ammunition. I dissected the cartridges and found that three of them contained the 35 gr charge and the rest, 40 grs. The powder had a polished appearance and screening determined that it was FFG granulation.
I annealed the cases and replaced the primers. I loaded the powder back into the cases. The 40 gr charges in the SHBP (Solid Head Button Pocket aka balloon head) cases required .20" of compression. I replaced the dried out lube on the bullets with SPG and reseated them.
Average velocity in a 7 1/2" barrel was 932 f.p.s. In a 24" barrel .... 1,247 f.p.s.
The three 35 gr. cartridges averaged 877 f.p.s. in the Ruger.
By comparison, velocities with 40 grs of Goex FFG ran about 100 f.p.s. less.
In further testing, only Swiss and Olde Eynsford FFG had the ballistic strength to equal the velocity of the powder used in those pre 1911 U.M.C. cartridges.
Here is a pic of a vintage 28 gr. cartridge box I found on the internet awhile back.
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