Can get some #2 at Macks, Simmons, Rogers sporting goods.com (free shipping most the time).
I doubt you find any #4 steel, smallest i've seen has been 2's. I use 2's for ducks, T's for geese, or BB's. Used to get some F's at a few places.
I was just about to tell you that. I ordered some for the hulls a few years back and just shot them for cripples (that didn't happen though) :biggrin:
I've been rolling my own now for a few years to really get the potential of the 10. There are umpteen threads about 10 ga reload recepies in the gun section at the fuge, but if you want to try something different and don't want to buy a whole case look up sportingammo.com and you can get some 1 1/2 oz 1600fps #4's. Just call the number and more than likely the guys wife will answer. They are very nice and the shells are kick butt!