RE: Fire forming 22-250
I would think that trying a method like Bullseye and a wad would be more hassle than just loading up the brass as normal and shooting them. So your groups aren't perfect, but the cost of .224cal bullets is very low, and using loaded ammo will assure that the case is, in fact, fireformed properly.
I can understand the logic of the Bullseye method when forming the large capacity, over bored cases that take a lot of powder and expensive bullets. But the 22-250 doesn't have either problem.