I just bought a can of APP gold powder in ffg wanted fffg but they didn't have any.I had been shooting 777 in fffg at 90 grains.Where should I start with the gold, bullet is 250 sst out of a Ruger 77/50.How much different is ffg from fffg.Should I take this can back and find fffg gold.I have always used ffg powders whether it be 777 or pyrodex.New here so be gentle.