I too have shot animals out to around 350 yards with center fire rifles but not a muzzleloader. I routinely practice out to 200 yards with most of my smoke poles and some of them do better than others. My older son's Apex shot a 3" group at 200 last time out using a 250SW and 130gr ofPyro pellets. I haven't tried any other loads in that gun yet. My MagBolt shoots several loads under 4" at 200 yards including the 460NE over 90gr of 777 2F. That gun likes the 348PB best so far and puts them into about 2.5" at 200 using 100gr of 777 2F. Myyounger son's Optima shoots the 250SW into about 4" at 200 using 90gr of Pyro P.

I am planning a trip to the range in the next few days if the weather holds up to try out my GPH and see if I get lucky on a load. If everything falls into place I will try it out at 200 and see how it does.

BTW all of these are 50 cal.