I am going against the flow here.
You are talking about a Bobcat, right?? Not a percision chunk gun or bench rifle.
:rotf: :rotf: :rotf:
Cast them up and shoot them up!!! You are not going to wear out your barrel using 45 pounds of wheel weights. In fact, I'll bet you are hunting for more of it before you use up what you have!!!
There is a layer of cloth between the ball and the bore. Play around with a slightly thinner patch than you might normally use in order to avoid loading difficulties and become the terror of the tin can shooters at your range.
If they cast on the light side it will only be one or two grains, not enough to worry over. You are casting all of them from the same metal, right?? You are worried about consistancy from shot to shot during a 45 pound run of metal (1300-1400 balls), not making radical weight changes in the middle of a target match!!!
I have a couple of guns that have been living on a steady diet of wheel weight metal for twenty years. They still have all their lands and grooves and still shoot well.