Thanks for the great response Eldeguello. I will definatly follow your advice with these.

Here's the response I received from Alliant (echoing your advice);

"The listed load is okay but we never recommend that you start with the
maximum load. We do recommend that the listed charge wt be reduced by
10% for a starting charge. Thanks for your interest in contacting us
and let me know if you have any additional questions. Have a nice day.
Ben Amonette
Consumer Service Manager
Alliant Powder Company"