Geno:
I too have heard about health risks involved with battery lead. Unfortunately, we hear about so many "dangers" these days it is hard to separate the wheat from the chaff. It is pretty well accepted that lead is not health food, and everyone knows about "Arsenic and Old Lace". Antimony is no better. You don't want to put this stuff on your breakfast cereal. All in all, ten pounds of lead is probably not worth taking any chances with. You might be better served, if you want cheap lead, is to go to the local garage and inquire about wheel weights.
From a strictly practical standpoint, the problem with battery lead, as well as wheel weight lead, is the unknown composition. Both uses require fairly hard lead, and this hardness is achieved with the addition of antimony or arsenic or both, depending of the price of the metals at any given time.
Rifles can be quite sensitive to lead hardness. I would be a shame to work up a killer load with an alloy and hardness that you could not easily duplicate. Also, the antimonial alloys tend to change hardness as they age. "Found" lead is best if you have a lot of it, all melted down and mixed together so you have a significant supply of uniform alloy. You will want to add some tin to the mix as well. Tin significantly increases the ease of casting.
On the other hand if all one is doing is making up some plinking loads, none of this matters(except for the health concerns). Shoot what you have, maybe add a bit of tin for casting and get out there and have some fun!
Glenn
