Jondh, I see you're a very new member here, so before answering your ID-request, first let me say, welcome to T-Net's "What Is It?" forum... the ebst place on the internet to get unknown objects CORRECTLY identified. (Never-ever trust what Ebay sellers say.)
Jondh wrote: > Minie Ball ID Please.
Just helpful advice here... by definition, a Minie-ball (named for its inventor, French Army Captain Claude Minie) is a conical lead bullet which has a deep wide cavity in its base, to enable the bullet to expand outward into the gunbarrel's rifling grooves upon firing. Your bullet has no such cavity in its base, so it i9s not a Minie-ball.
Smokeythecat and RustyRelics are correct... the tiny multiple parallel ridges inside the body-grooves on your bullet first show up on bullets around 1877. That characteristic is called a "reeded groove" or the more technical name, "knurled canellure." Reeded body-grooves are still being made ion bullets today.
Your bullet appears to be from a metal cartridge. It diameter appears to be somewhere between .40 and .44 caliber. It is probably the latter, because .44 bullets are far more common than .40 bullets. The by-far-most-common .44 bullet is the famous .44 Colt APC, made for use in US Army Model-1911 Colt pistols, Thompson machine guns, and several other 20th Century .44-caliber firearms. Without knowing your bullet's precisely-measured diameter, that's my best-guess for its correct ID. Please try to borrow a digital caliper, to make the very-precise measurement we need for identifying your bullet with more certainty.
All .45 ACP (Automatic Colt Pistol) ammo I have seen was copper jacketed. Thompsons will not cycle well with lead nosed bullets. CBG did you somehow keep mistyping a 4 rather than a 5? No Thompsons or M1911s IN .44. Looks like a .38 wadcutter to me that has been deformed by impact.
Gunsil, thanks for the correction. I had dental surgery (for an implant) a couple of days ago. The errors in my post show I probably shouldn't try to write a "detailed" relic-ID when I'm under the influence of serious pain-meds. :-/