The kind of powder that's correct for this gun is smokless nitrocellulose powder, but as has been mentioned it's NOT meant for moder, high energy smokless powders.
For a number of years after the advent of smokless powders, companies such as Du Pont and King's offered what were called bulk smokeless powders.
These were low energy smokeless powders that could be used volume for volume the same as black powder.
In other words, a shell that was loaded with a scoop of 3 drams of black powder could be loaded with a scoop of 3 drams of bulk smokless. Generally these smokless powders would generate about the same pressure as black powder, too.
Today's powders have to be measured in dram equivalents.
Bulk powders haven't been available since shortly after World War II.
Today the closest thing we have to a bulk smokless powder is Trail Boss. It's close, but not close enough.
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