muzzloading can be frusrating.first you nedd to shoot the same load everytime,second you must make sure you seated the charge and bullet the same everytime.third you should clean the barrell after each shot when sighting in.also you need to be shooting from a steady rest/bags ,sled.This is a time consuming process that most people rush.What is the charge and bullet combo?try backing down if you are shooting the full 150 grains.when i got mine the first thing i did was load it to the max shots went everywhere then it started to hurt,a big NO NO.i backed down to a 100 grains and my problems were solved.I would also suggest shooting from 25 yrd just to get your groups together then move out to 50 then 100 yrds.Have you tried shooting without the scope and just the iron sights?if your getting groups without the scope its the scope.try to eliminate all the variables(remeber algabra?)good luck and get back to the range.
Now therefore take, I pray thee, thy weapons, thy quiver and thy bow, and go out to the field, and take me some venison.
Genesis 27:3 "The thinking deer hunter should mature through three phases during his hunting life. First phase, "I need to kill a deer." Second phase, I want to harvest a nice deer. And last phase, we must manage this resource so our children and their children can experience the grand tradition of good deer hunting." - Jim Slinsky