Wow, how much & why?
Is your question how much nitroglycerin?
Smokeless powder is a mix of high-nitrogen nitrocellulose (guncotton) and nitroglycerin, with a coating to make flow easier, retard ignition, and reduce static sensitivity. There are triple base powders that also contain nitroguanidine.
As for how much, that varies.
Why? nitroglycerin is a pretty good way to store energy, if you wish it relesed in a very short time. The mix between the propellants, the grain size, and the coating all contribute to controlling barrel pressure and burn rate.
Extracting the nitro is very dangerous. Nobel got his money by mixing it with stuff to make it safe, I think it's better to keep it that way.