Asking on behalf of someone else and this is the info he provided:
Thanks for any help. I don’t have any idea myself.
I have a 3 inch projectile about 11.62” long, weighing about 14.6 pounds. Markings are:
L 5313- UPC 3IN. 15p MK VII 1442. Lightly stamped just above the copper driving band.
The body appears to be solid steel with a single rear located copper driving band. It is more pointed than photos of other 3 inch projectiles that I have seen, similar to a 30-06 150 gr. flat base ball bullet. It appears to be made of sold steel, with no openings. There is no paint. It may be chrome plated. I’m not sure. There are many small rust spots on the surface. Can you please help me identify this projectile, and tell me the proper way and color it should be painted, and any markings it should have? I am guessing that it is a practice or non explosive AP solid steel projectile for a relatively late Navy 3 inch MK VII gun.