Back in the 80s when I built my .54 caliber flintlock my first hunting load was 120gr FF Goex...I used this a few years and then went down to 100grs FF Goex...The past 10 years or so I've used 80grs FFF Goex...They all killed deer...

My Knight prefers (until last night) 80grs FFF Goex...With 250 Shockwaves and 300gr Hornady .430 XTPs I've killed about 15 deer with 80grs of FFF Goex...

Out to 150 yards there won't be enough difference in velocity to make much difference in trajectory...

Remember the 45/70??? That used a .458 caliber bullet that weighed 405grs...Big, slow and killed the heck out of plenty of buffalo...

I guess if I was a fellow that wanted to shoot muzzleloaders out to 200 plus yards, I'd worry more about velocity...But frankly, I'm not, I know where to set up on our farms to kill deer within 100 yards...

Heck, if I wanted to kill them further with a muzzleloader, I'd drive up to Greensboro and have one of the Bells make me a smokeless gun or pick up a used Savage...