You can do it. My H&R actually groups better with rifled slugs than it does with most modern sabots. It does make one heck of a mess though and the barrel fouls out after about 4 shots.

However what you want to do really won't work. If you are going to use sabots in the end, start with sabots. The point of impact could be different when you switch rounds. It is not uncommon for my gun to shift impact points by several inches when I try a different type of ammo.

If you don't want to spend the money try bore sighting the rifle. Put it in a rest and look at a target 50-100 yards away. Center the target in the barrel, then look thru the scope. If it is off quite a bit adjust it, or better yet shim the scope until they point in the same spot.

That should put your first shot on the paper at 25 or 50 yards.

I really wouldn't make any fine adjustments until you find a load you like. Once you find one that groups well at the distances you want to hunt zero your scope with that load. You don't need the bullets to go in the bull to see how they are grouping, just so long as you aim at the same spot every time.

Paul