Only a few of the smokeless options give a excellent burn percentage. Those typically spike psi faster and use much less powder. Slower powders need more powder to make enough psi but end up running out of barrel without some load work. Using smokeless some people use a duplex charge to over come this. A small booster load (10gr) of faster powder first then the slower powder on top of that.

Kinda makes me wonder what 10gr of T7 under 100gr+ of BH209 would do with a 200gr bullet in a 45cal ML. Im curious but im not sure i want to try that one.