RE: 150 grains of 777 in an CVA Optima Pro .45?
If you can use sabots in your state, i'd ask around and find one. Other than powerbelts, theres the 285 grain great plains bullet for the .45, tc maxi hunter, tc maxi ball. I wouldnt use either of those TC bullets in a .45, i used them my first year muzzleloading with a .45 and they just plain sucked when they hit deer. I lost a huge one thanks to the maxi ball. Thats all the bullets i can find in the cabelas bible. A lot more choices for a .50cal.