777 in a 10 ga

[Cold Spring]

I haven’t tried 777 as yet but have studied its chemistry, thinking of loading 12 gauge Federal paper hulls/fiber wads with it. Keep in mind that “dram” (relative to gunpowder) is a unit of weight, and that 777 is more energetic than an equivalent weight of black powder. That’s because its primary oxidizer is a perchlorate not a nitrate as in BP. Thus a 3 dram load of 777 will generate more pressure than 3 drams of BP. Well in any case for safety sake I urge you to contact Hodgdon for vintage 10 gauge load recommendations with 777 before starting out.