These 50BMG rated targets are constructed of 3/4" AR500 steel. The target is designed to keep the chain and mounting hardware away from the shooting surface. This will extend the life of the chain and mounting bolts and yield less down time for repair. The target is designed to accept 5/8" bolts as a mounting method. Ratings:50BMG ball and brass solids - 300 yards50BMG Improved - 400 yards50BMG AP and API - NOT RATED416 and 408 lead core - 300 yards416 and 408 brass solids - 400 yards The rated ranges are a minimum. You may need to move the target back based on your specific load and barrel length. Keep in mind these rounds are designed to go through steel!! DO NOT under any circumstance use closer than the rated range. The projectiles for the most part are either steel core or solid brass. The bullet "splash" can be very dangerous at close range. DO NOT use any armor piercing or incendiary bullets. Full wrap around eye protection is required by the shooter and any spectators in the area. Objects near the target will get damage by the splash and can cause ricochets. Remove any unnecessary objects from the shooting area, including in front of , behind and to the side of the target. In addition make sure there is a proper back stop behind the target to stop any misses. Note: Shipping is priced to the lower 48 states. May ship via USPS or UPS depending on the contents of your order.