Burn rate, "Quickness" and ENERGY CONTENT (by weight or by volume) may or may not be related to one another.
My money is on the not related.
Unless you have your own ballistics lab, pay close attention to the published, authoritative loading data. Deviate from that under advisement and very cautiously because stretching the established performance envelope is even more at your own risk than loading your own.
Reloading is not rocket science, but it does involve smoke and flame and objects and event that move and happen very fast.
Be safe. Always, all ways.
Lost Sheep