Lagopus-
That sounds right.
FFg is often referred to as 2f -- and it's typically used in shotgun and rifle charges in the 12bore - 16bore neighborhood.
The rifle that I'm loading for (and that brings this question to you) is a 16bore Westley Richards.
I've gotten to where it's shooting right and I want to translate my Goex FFg charge to proper period Brit Drams
To brew it down further, it looks like they'd have called this one a '5 Dram' rifle, but I'm curious to see how many grains of Goex FFg fits into a mid-19th century powder measure at it's perscribed designation in (number of) Drams.
Got one that says 5 Drams?
Throw a charge and weigh it.
Got one that says 3 Drams?
Ditto above.
Four or two or whatever, I can do the math and get to a relative place.
Cheers
Tinker