Have any of you used this powder? If so, I would appreciate any info you might share as to caliber and comparisons.

I have not used the f(fast) lots of it but IIRC it was advertised as H380 speed, you could contact Jeff Bartlett and ask, or see which companies name is on the label and contact them. I shot a couple jugs of 852 the slower speed that was advertised as 4831 speed,it was same powder as H450 I had.