I shot mild steel targets for a long time.1/2 plate.but now only have reg steel on one target at 958 yards. It has taken many rounds from big 7s,300,and 338 imp. It looks like hammered hen **** but works.But have progressed to ar 400 1/2 plate for all my targets from 280 yards to 1400 and every where in between and am very happy with it.the mild steel wouldn't hold up much below 800 yes with my setups. I go some quality
compound bowstrings from proline to hand it with. I do have a disk blade set up I use for mile shots but wouldn't use it much closer than 1200 yds. Just my thoughts.I think a 4x8 sheet of ar 400 cost me around 400-450 bucks and I just plasma cut targets and hang them on t posts works great.