The OP established that it’s not an empty casing, but is it just a bullet, or is it an unfired round of ammunition? Those two terms don’t mean the same thing, do they?
“Bullet” technically only refers to the projectile (the thing that gets fired out of the barrel). “Cartridge” (or “Round”) refers to the entire, complete thing- case, primer, powder, and bullet; all present and correct. An empty casing on its own is exactly that- a “case”, or “brass”.
If you want to get super technical about it, there are people (I’m not one of them) who will argue that “Bullet” only refers to a specific type of projectile, typically one with a rounded nose (like you see for use with Old West guns). Projectiles with a pointed tip (like most rifles cartridges use) are Spitzers, and hollowpoint projectiles are, well, self-explanatory.
Well, that’s well beyond nitpicking and halfway into OCD. None of the large ammo and reloading supply manufacturers call their projectiles anything but “bullets”. Cite, cite, cite, cite, cite and cite. And another cite.
To the OP: A live round is no biggie (a bullet is even less, as has been pointed out by others, that’s just a slug of metal), but if you’re not able to destroy the evidence in a safe manner yourself (i.e. shooting it in a gun chambered for that cartridge), I’d hand it over to proper authorities for safe handling. An inventive 12-year-old might just lose half of his eyesight by doing fun things with it.
ETA: The last paragraph is from experience. I’m quite amazed that only one of my then-buddies blew out one of his eyes playing with that stuff. :eek:
Damn, where do you live?
I’m not disagreeing with you, just mentioning that, given this board’s penchant for having people disagree with others for the sheer hell of it, if I didn’t mention there were people out there who did differentiate between different types of bullet, there’d be someone in here saying I had no idea what I was talking about because I didn’t mention it.
Instead I do mention it, and get someone implying I don’t know what I’m talking about as a result. Le Sigh; I really don’t know why I bother sometimes.
I didn’t mean to indicate that you didn’t know what you were talking about, and if my post could be interpreted that way, I apologize. My comment was directed towards the people (of whom you’re not one) who will argue that “Bullet” only refers to a specific type of projectile.
That’s OK; It’s just that providing over half a dozen linked cites against a fairly simple, off-hand observation just reads (to me, at least) as a form of saying “WRONG! JUST BRIMMING OVER WITH WRONGABILITY! HERE’S THE ACTUAL ANSWER! DON’T LISTEN TO THAT OTHER PERSON BECAUSE THEY’RE WRONG!”.
I’m sure that’s not how you meant it to come across, of course, and it’s all good- just saying that even here, not everything needs to be treated as though it’s a component of a postgraduate thesis or dissertation. 
I didn’t mean to spark off this argument - it just wasn’t clear to me exactly what it is the OP had found, and whether the concern was one of safety, or if it was a concern about handling something that might be criminal evidence, or something.
It’s a complete, intact round as shown in the picture I linked (which isn’t the one I have but identical in appearance).
Opinions seem to be evenly divided between “give it back” and “toss it in the trash”. I suppose I should err on the side of caution and drop on by the trooper’s house though not with any great concern.
I find it odd that a trooper would carry munitions in a manner where it could spill out. I’d take it back to him just so he knows it happened. If one fell out then there may be others which creates a dangerous situation with a lawn mower. I’d tell him this specifically so he realizes the potential risk.
You can drive your quail hunting buddies nuts by calling shotgun shells ‘bullets’. So of course, I call shotgun shells bullets.
You just brought back a childhood memory: I found a bullet near my house one time when I was a small child (I’d say somewhere in the 7-9 age range). I carefully picked it up, took it in the house, and gave it to my mom, proud of myself at how good and responsible I was being by turning it in rather than playing with it.
I got spanked.:rolleyes:
I don’t think I ever forgave my mom for that one, because she didn’t really communicate well with me why was getting spanked and what I should have done.
It was weird, too, because Mom wasn’t usually that weird about stuff. That one set her off for some reason.
Isn’t that the real reason Dick Cheney shot his friend in the face?
He did get his apology…
Heh. When I was a kid a friend and I found a pocketful of .22 LR hollowpoints, and I thought the same thing. When I got home my dad corrected me on that one, and they phoned my friend’s parents to let them know that Andy also had a pocketful of live ammo. This caused some distress, as his mom hadn’t checked his pockets before washing his pants and throwing them in the dryer. 
It could be put through a compactor in the garbage truck and be crush against something hard which could cause it to go off. Low probability, but possible. I’d say disposing of it in trash is a bad idea.
You know, if you put a bullet in the furnace, it will explode…
[/Cosby]
Your mother must be pretty low down for you to put a bullet in the furnace.