RE: bullet Question
As stated earlier, you can't assume 2 different bullets, even if they were the same weight, would have the same POI. HOWEVER, I see no reason why you couldn't sight in your rifle with a powerbelt to find the "sweet spot" of powder charge, then spend the off season practicing with cheap bullets. That way, you can develop good habits for shooting your gun without spending a ton of money. Then, 1 month before the season, start shooting powerbelts again, so you can readjust the sights for them.