>>64081478
yeah, steel or iron shot would be great for that. It's cheap, it's safe, it's recyclable, it's easy for machinery to handle and sort with magnets.

>>63989641
>Got any pics of the rifle you used?
It was a State Arms "Mach V". From the outside it looked exactly like their "Competitor 2000" model though the barrel was slightly longer (40").
http://www.statearms.com/rifles/competitor_2000.php

I still have a couple pieces of the brass kicking around, 3rd from the left in this pic.