Due to the current ammo situation I have been loading some ammo for some people and had to go test some loads I put together.
First and very importantly this post would not be possible without the generous karma gift of the chrono from @Paul D a few years back when my own chrono died. So a BIG thanks to PAUL D!
The load tested was 4.7 grains of Unique and a 148 grain hard cast SWC from Rim Rock.
The 1&7/8ths" S&W 442 they averaged 750 fps (749.8).
Accuracy at 7 yards was fair enough, considering I was just test firing.
The 4" Model 15 Combat Masterpiece they averaged 820 fps.
The 6" Colt Official Police they averaged a hair under 900 fps(897.5).
The old Official Police still plunks the right in there.
Overall the SWCs will make a good J Frame load for friends who need it. I am about to do the same load 4.7 grains and substitute the 148 SWC for a 148 wadcutter and crank out about 500+ of them for friends who carry J Frames. Should be the same velocity. Good little pocket gun load.
.