The video gives a good explanation. I think that it is also interesting that the “active ingredients” in nearly all “smokeless” powders are nitrocellulose, and/or Nitroglycerin, and/or Nitroguanidine with various “stabilizers” which are basically absorbed into granuals of various shapes and sizes. That is why every time you open a continer of smokeless powder you always almost get the same familiar odor.
The shape and size of the granuals are designed for both burn rate and also ease of metering in some cases. Of course there are volumes of information on both the chemical and physical properties of various smokeless powders. They are produced by various processes.
As he said... it is very important to keep meticulous notes on your recipes when you are doing reloads with smokeless powders. They are designed with som many different burn rates and other characterisitics. There are many powders that take only half as much to get the same velocities out of the same cartridges. It is very fun however to test new recipes using your chronograph and various projectiles. You can spend hours experimenting to find the perfect combination.
I cast my own bullets also and he is right... sometimes times the type lube you use on them can make almost as much smoke as black powder especially if you are casting rifle bullets with lube grooves and gas checks. But it still is not as messy. It is a very fun and interesting hobby.. and saves money.. although sometimes if you figure how much you can put into equipment and supplies... it is along the same lines as how hunting and fishing reduce your food bill in the lower 48.
Crisco works for lube,smells like frenchfries!