What powder would you recomend for 1000 fps out of a 4 5/8 blackhawk? I've always used 18.5 of 2400 with bull-x 255 grain swc at 1100 fps, but when I tried this with the beartooth 255 wfn I got 950 fps with a 150 fps extreme spread. Maybe because the bullet is shorter I need more powder to get consistent velocity? Maybe a magnum primer? Does anyone get good accuracy with this bullet? Thanks
BC

I would just work up a little higher on the powder charge.  If you are getting less velocity, then it is very likely that the pressures are too low to make the 2400 burn properly.

This is a pretty light load for a Blackhawk.

try 10 grains of unique it should be close

LLoyd is just about right on, for I get 850 fps with 8.5 grs. of Unique and a 255 swc in my 45.you seem to get a 100 fps for each grain

The 1cc Lee dipper of Universal is what I use. I hit it at about 9.5 gr. But that is max for a 240 gr. FPJ

Ignore this post. I just read your question more closely.

Thanks. I'll give unique a try.