Photo not good enough to tell for sure but my first impression is a .45 ACP round nose jacketed bullet, known as a full metal patch by the armed services. The open base of the bullet was common and I am guessing it was cheaper to make than one with a complete jacket because of the shortage of copper during WWII. Monty
We were pulling up some old wood flooring in the unfinished section of the basement in my old church and I came across five .45 ACP casings that had been there a LONG time (church was built in 1881). One never knows. The town park I most often hunt was a corn field 30 years ago and I turn up all kinds of bullets abd brass.
The bullet looks like it never hit anything with full velocity.
A lot of people like to shoot up in the air, whether a celebration, or just acting foolish. Luckily no one was under this when it came down; if it was a result of a "yahoo-bang".
Where do you think I have found most of my bullets while hunting about town? Why in the sand at the playgrounds, of course! For some reason there are morons that go to the city parks to test fire their guns! It's nuts, but true. I'll bet many more Tnet members have found the same thing. M nty