I know that in certain situations with certain calibers, shooting plain steel plates is bad. If I plan on shooting steel with a 308, at 66 to 300 or 400 yards, does it continue to matter if I am shooting that 550 alloy steel, or whatever it is? Or would a plain hot rolled piece of steel be ok? Also, what sizes do you guys think for 100, 200, 300, & 400 yards? Any good sources for that hard alloy steel if needed?