"Very Early" smokeless loads were not I believe marked with Dram Equivelents. Many of the early smokeless powders were bulk powders & loaded by bulk measure equal to BP so the load was simply stated in drams, though technically dram is a weight & not a volume. A Dram Volume was settled upon as .115CuIn. Most early shells loaded with dense smokeless were simply marked with grains of powder. Most shooters had no idea what this compared to so the decision was made to use the DE marking to reference BP. This was as has been stated solely on velocity & had nothing to do with pressures. Somewhere I have an extensive chart of velocites for different DEs with various loads of shot in each of the ga's. About the only one I can consistently remember is a 3DE-1 1/8OZ in 12ga is a nominal 1200 FPS. The Boulenge Chronograph dates back much earlier than many are aware of & it proved the correctness of the ballistics pendulum.
