4g to cannon grade

[Randell]

Any safe way to turn 4g black powder into cannon grade size

[crow_feather]

Not any safe way - except to trade it for someone elses cannon grade.

[John Boy]

Randell, the answer is no.  FFFFg powder is a much smaller grain size compared to Cannon powder.

Sporting Grade Black Powder -- "g" type powders
Powder Grade    pass screen,  holding,  stays on,    passing

Whaling          32/64" mesh    3%        4 mesh        12%
Lifesaving        6 mesh        3%       12 mesh        12%
Cannon            6 mesh        3%       12 mesh        12%
Saluting         10 mesh        3%       20 mesh        12%
Fg               12 mesh        3%       16 mesh        12%
FFg              16 mesh        3%       30 mesh        12%
FFFg             20 mesh        3%       50 mesh        12%
FFFFg            40 mesh        3%      100 mesh        12%