Material for inlet covers shall have the following chemical composition: 67-71 pct copper with zinc remainder; 7.21 in. Long; 5.619 in. Inside dia; 0.031 in. Thickness all around; 144.0 in. Radius; 0.72 in. Nose circumference; inlet cover used for 16 inch 50 caliber projectile mk 8 all mods or mk 10 all mods