Joel touched on an important issue, when I load buck and ball I try to keep the total projectile weight near the weight of the heaviest conical made for the bore of gun I am useing,the wads/are also a factor in resistance, not scientific but a place to start, when putting a ball atop the shot for a shot at a pig at close range 20yds +or- the ball may hit the pig, one would have to field test for accuracy, the strength/type of barrel should be considered, use caution when testing any "odd" loads. When hunting I would opt to dump the shot and drop a ball in its place if time allowed, I have a Virginia smoothrifle with a barrel that is 1 1/8" at the breech, swamped oct by Getz in .62 bore size it can take a pretty stout load, probably more than some other smoothbore barrels we have been chatting about lately, the barrel you have would be the first concern IMHO when loading this kind of load combo.the stle of gun could also make it a hurtfull load to shoot, may cause you more discomfort than the pig, just some thoughts.