Hank,
Generally, if the barrels "shoot apart",the load needs a little more velocity(more powder or lighter bullet), but if they "cross" it needs less.It's important to know which bullet made which hole, and you may have to shoot each barrel at a different target to do it(you should shoot the second barrel as quickly as you can get back on target).The powder shown on the gun(Curtis & Harvey #6)is considered a more powerful powder than is avaliable now, so you wont't likely wind up using the same load.This doesn't mean the rifle is out of regulation.
Mike
