I use Lee. No idea base size. I disagree with the comment about just creating generic factory loads.

Whenever you try different powder loads you are going past good enough factory. I would argue the same could be said for the bullet you use. But you could spend $$$ a get higher end bullets too. Then there is seating depth.

I realize I am not are a long to reach the maximum, but I am past factory.

I have heard people say to use small base for pump rifles. But you hear lots of BS about pumps that is not true.