As Larry said the pressure curves run by DuPont in the 1920s do show very similar curves for all powders tested. With shells loaded to give the same shot charge the same velocity, those loaded with Infallible, Ballistite & Dupont Bulk Smokeless showed a higher "Breech" (Max Chamber) pressure than 3f Black, but a slightly "Lower" pressure for the rest of the barrel.
DuPont Oval, one of our First "Progressive" powders show a lower max pressure than even the black, but a slightly higher barrel pressure.
The bottom line is "IF" you give the same shot load the same velocity, you have done the same work. This translates into the Fact, that the average pressure for the entire length of the barrel is essentially the same, It is just slightly re-distributed.
The Major difference in Black & Smokeless is that black burns at very much the same speed regardless of circumstances. Also due to the space it occupies it is near impossible to Overload with black. It is Highly suspected that many barrels were burst in the early days of smokeless by Re-loaders who Measured their Dense smokeless powder with the same bulk dipper they had used for Black &/or Bulk powders. This would give from a double to a triple charge of these dense powders, took a strong gun indeed to hold such pressure, whether Steel, Twist or Damascus made little difference they all Burst under these loads.
