The "first printing, 1970" version of the Speer Reloading Manual #8 tested the Auto Rim in an S&W M1955 Target revolver with a 6 1/2" barrel, and got some startling results. Cases were "WRA solid head" and CCI 300/CCI 350 primers were used.
In my opinion, these loads are too hot, and under no circumstances would I load them up and try them in my own S&W M25.
A 240 grain cast lead SWC got 1192 ft/sec ahead of 13 grains of Norma 1020 powder, and 1185 ft/sec over 10 grains of SR4756.
A 200 grain Speer soft point got 1345
ahead of 14.0 grains of SR4756, and 1330 in front of 11.5 grains of Unique.
A buddy got a later printing of the #8 manual, and it seems that all the SR4756 loads had been deleted. Hmmm . . . even that Unique load looks like it's around 3 grains heavier than anything I've seen elsewhere.
I've used SR4756 in .45 and other cartridges, but at charges MUCH LESS than those in Speer's #8 manual, which probably even exceed proof load pressures.
If anyone reading this decides to try these loads, please post a picture of whatever's left of your revolver afterwards.