I may have posted this in the wrong section.
Trying to find an I.D. or Date on this Case, I am new to the community but have always had an interest in vintages items.
I found this in the Western Ny area.
Left behind from an older tenant in a trailer park development.
It is a solid-shot (not hollow explosive) Armor-Piercing projectile, from the World War One era, but possibly as late as World War 2. The multiple short parallel ridges on a raised copperbrass belt encircling the projectile's body are rifling-marks made by the rifling-grooves inside the cannon's barrel. That means you projectile has been fired. The small shallow hole in its base held a small amount of Tracer chemical, which burned very brightly when the projectile was fired, showing you the projectile's "flightpath." Tracer ammunition helps the gunner adjust the gun's aim.
It appears to be what is called an Armor Piercing Ballistic Capped (APBC) projectile. See the diagram below... which shows a smaller version than yours.
If you can give us a PRECISE measurement of your projectile's diameter at its widest area (not including the raised band-sabot with rifling-marks), in millimeters or hundredths-of-an-inch, we may be able to give you a more specific identification for it.
As CannonballGuy said, it's a solid shot artillery shell, with tracer. Without a measurement, and just based on a comparison to your hand (assuming you have average sized hands) I would offer an educated guess that it's a WW2 U.S. 75mm shell. If so, it's most likely for the US M2 gun which was used in the M3 Lee tanks, or for the M3 gun which was used in Sherman tanks. I say that because those are the most common rounds likely to be found that would be the size of the one you have.
An accurate measurement as mentioned above, adding length and weight will help either confirm that, or start a new search for a match.
The paint is not original by the way, and if I had it I would definitely remove it
EDIT.... If you look closely at the driving band, (the part with the grooves) even though it's been fired there may be visible markings still on the high parts. The gun barrel may have wiped them clean but I have occasionally seen some still visible numbers on them. You may have to strip the paint to see anything, but if there are any partial numbers left those could help