The headstamp reads,1.58 on top, the initials TH to the left of the rim, S to the right of the rim. On the bottomof the rim is what appears to be 7.62, a greenish sealer around the primer. Bullet is FMJ with tin as it draws a magnet weakly, black sealer around crimp with a brass case, not blackened. Got 40 of these with a bunch of ammo in a garand deal along with some other black tip AP. I,m guessing, made Jan of 1958 with a .308 bullet but I do not know what the letters mean----does anyone know the arsenal or manufacturer???, THS on the rim.