Shot that stuff for years, same can with a rubber pull-up stopper.

It is not as good (STRONG A powder), as the current GOEX, Wano, Elephant and certainly not the more expensive Swiss, Schutzen & Ennisford.

I would use another 1/4 to 1/2 dram to make up for it.

I also use 2F for 12's, etc. I have tried 1F - in modern GOEX and 1 1/2F in Swiss for the .50/95 and .45/60 BP loads, but it the 1F C&H does develop lower speeds, with identical loads. Best to make that up - 1/4 to 1/2 dram.

A chronograph is your friend.