At this point, due to the low-quality photo, the bullet is looking to me like a fired .45-70 Springfield Rifle bullet.
Also, whatever kind of bullet it is, we can't estimate it's age until we see whether its body-grooves are "reeded/knurled" (have multiple tiny parallel ridges in hem), or are plain.
Here's a photo of a bullet with a "reeded" or "knurled" body-groove. If your bullet's grooves look like this, it is no older than about 1877, and probably a good bit younger than that. (Bullets are still being manufactured today with reeded/knurled grooves.)
Scaling from the tape measure, that bullet is ~ 0.5" diameter & over an inch long before it impacted.
Also, Oldtimer82, the groove style of the bullet TheCannonballGuy posted is called a cannelure. Look on Google images for it and you'll see nearly every conceivable variation. The reason the groove is there is for lubrication.