Smokeless Starting Point In Black Powder Rifles

[jonp]

In the April 2020 Handloader a question on page 16 was asked about loading the 40-50 Sharps Straight using 40-50 Sharps Bottleneck data. He said that although they use different cases the capacity is about the same so go ahead.

Brian Pierce replied to the question: " as always when using smokeless powder loads in black powder eaa cartridges start around 5 to 7% below maximum charge weights and work up carefully to Maximum listed data"

I'm assuming he is referencing modern reproductions?

[GregLaROCHE]

I would think that with the same charge, a bottleneck cartridge would have higher pressure than a straight wall. Maybe the manufacturer can give you some advice, if it is possible to contact them.