If you are just looking to use them instead of boresighting they should be ok to get you on paper up close. However at longer distances they may have a slightly different impact point. It is not uncommon for my gun to shift impact points when I change ammo. So you would still need to sight in with whatever ammo you decide to use.

You will also have to clean the barrel very well when you are done, and accuracy may fall off after 3 or 4 shots. It won't hurt it though, just makes a mess. I actually hunted with brenneke rifled slugs out my fully rifled rifle last year. Mine actually shoots some of them pretty well...., for about 4 shots.

Paul