With out knowing what you are shooting that is difficult.
Some guns have a lot lower charge limit than others.
I assume you have an inline;for long range accuracy I would recommend the 50 / 40 - 200ge Shock Wave if you have a 50 caliber inline read the operators manule start at about 70 gr [RS,FF,APP=FF ect] and go to the limit of your gun keep your targets and compare them if you don't have good enough accuracy for the range you want to shoot try a different powder if that dont work try Hornady SST bullets.
Its a matter of what that particular gun likes you can have two guns that appear to be exactly the same and they will still like different loads or different powders or bullets. Lee