Learn from my (small) mistake. When you derive a new load, make a small batch and test it before you make 2 boxes.
Also, my file host is acting up again, so now I have a secondary link in each posting so you can download manually.
A listener, Todd, sent me these links to charts showing the relative burning rates of different powders:
http://www.reloadbench.com/burn.html
http://www.hodgdon.com/burn-rate.html
THANKS, TODD!
If you have trouble downloading, here's the file at a secondary location:
Episode 40: Test Your New Loads