I don’t know on the powder yet, thats why I am trying to see if BH209 is temperature sensitive. The Arrowhead muzzleloaders I thought was shot the BH209? As of now I am shooting the CVA Optima V2, 120gr BH209, 290gr TEZ, and it shoots about 1 MOA out to 300yds. After that, I am out of energy and haven’t shot past that. So I want to go to an ELR set up. I know with my .338 Edge at ELR, temperature stable powder is important, and I am guessing it is the same with a muzzleloader? I want to stretch my muzzleloader out to that that 800yd mark(not at game), but also have sufficient energy at those ELR ranges. So if the Paramount is only capable of pushing high two hundred gr bullets at velocities of 2000-2200fps, I will go to a custom build. Trying to get as much info as I can. Thanks again