question for the reloaders here; I am looking for suggestions for a subsonic load for a 45/70. I plan to use Hornady 500 gr jacketed bullets. Barrel length is 16.5". I am thinking a fast powder so as not to produce to much gas volume as I would like it to be quiet also. And should i consider using a case filler as there will most likely be a lot of empty space in front of the primer.