I'm fairly new to long range shooting, and I have some questions about the steel targets I see guys on Youtube shooting at. 1. I see the AR 500 steel is commonly used. Can I shoot 223 and 308 ammo at 300+ yards at 3/8" thick AR 500 plates, or do I need the 1/2" or thicker? 2. Who has the best deal / value on steel targets? 3. Is there a comparable grade of steel I can go to the local steel provider and purchase a scrap piece and make my own targets? 4. What is the best size plate to use from 500 to 1000 yards? Thanks for helping.