Originally Posted by MontanaRifleman
Yup, a standard disclaimer.
Back to the question....
The biggest problem with a closed bomb test chart or even a simple powder rate chart is there isn't any real world data there to differentiate how powders act while being constricted differently, how much load is on them, how much pressure you will hit at peak, etc..
A good example of two rather similar powders having differing burns in different calibers is rl22 and I7828. In my 7rem they are similar with 7828 acting slightly faster with mid weight bullets. In my 300 win I 7828 is slightly slower burning than rl22. In my 270 using identical charges (on the run up) of I 7828 and rl22 (since the books do) a top charge of rl22 loosened a primer pocket while I 7828 is a 1/2 moa load and well within pressure bounds. I've fired 200 of them in the last few years.
A burn rate chart can get you in the right class of powder, but using it to approximate charges is downright foolish. A better route is to find data in a slightly smaller cartridge or data with a slightly faster powder and consider your starts from there. You need the constriction and basic loading of the powder to make any sort of educated guess. Also do not substitute ball and stick powders as the bullet weight and pressure slow the two powder types down differently.