Why is it called ball ammo? I found this pic on the ammo oracle's page and I haven't figured out where the ball comes into play and that got me thinking about why is it called ball ammo. Thanks for the help guys.  
http://www.ammo-oracle.com/images/556ap.jpg

I am a little embarassed to say I would also like to know since I'm not sure.

Dates from back when bullets really were balls - lead balls, to be exact.

Until the mid-1850s or so, most ammo was actually a ball, a lead ball. The name has simply carried over to mean any general-purpose ammo, either jacketed or lead, regardless of shape. If you look at the tip of .45 ACP ball ammo or good old .38 spl lead round-nose, it does look like a ball, even though we know that inside the case it is cylindrical. Same for rifle cartridges, although they tend to be pointed -- if it's not armor-piercing or hollowpoint or jacketed soft-nose or some other specially named round, then we still call it ball ammo.

It's kind of like the term tin-foil. That stuff has not been made from tin since they figured out how to do aluminum cheaply, but we still often call it tin-foil. Most of us have never seen tin foil. I don't think I have.

Quoted: Until the mid-1850s or so, most ammo was actually a ball, a lead ball. The name has simply carried over to mean any general-purpose ammo, either jacketed or lead, regardless of shape. If you look at the tip of .45 ACP ball ammo or good old .38 spl lead round-nose, it does look like a ball, even though we know that inside the case it is cylindrical. Same for rifle cartridges, although they tend to be pointed -- if it's not armor-piercing or hollowpoint or jacketed soft-nose or some other specially named round, then we still call it ball ammo. It's kind of like the term tin-foil. That stuff has not been made from tin since they figured out how to do aluminum cheaply, but we still often call it tin-foil. Most of us have never seen tin foil. I don't think I have.

Or Tin Cans for that matter.

Quoted: Why is it called ball ammo? I found this pic on the ammo oracle's page and I haven't figured out where the ball comes into play and that got me thinking about why is it called ball ammo. Thanks for the help guys.   www.ammo-oracle.com/images/556ap.jpg

Technically, that pic from the Oracle isn't Ball ammo. Its M995 Armor Piercing .
As was stated earlier, the term "Ball" comes from the timeframe when rifles fired a round lead ball.

Thanks guys, I was leaning towards that as the reason but certainlty did not know for sure

Ball Ammunition: Ammunition whose bullet or projectile is designed with a tough metal covering or jacket over a central core material, and which is designed to remain intact and essentially undeformed on impact with an object at its designed velocity.

Plain Language Definition - ammunition which has a solid or fully jacketed bullet which does not expand significantly on impact with an object.
HTH

In military terms, it refers to any small arms projectile that has no exposed or expanding tip, i.e. the jacket material covers the tip in one piece down to the tail of the bullet.  

Another thing to think about is that the term "full metal jacket" isn't true either. The jacket actually does not cover the base of the projectile.  

Quoted: Ball Ammunition: Ammunition whose bullet or projectile is designed with a tough metal covering or jacket over a central core material, and which is designed to remain intact and essentially undeformed on impact with an object at its designed velocity. Plain Language Definition - ammunition which has a solid or fully jacketed bullet which does not expand significantly on impact with an object. HTH

And that's only the modern, derived definition, based on the original lead balls.  In fact, the early conical bullets were called "Minnie balls" because "ball" is what the projectile always was.

Quoted: Another thing to think about is that the term "full metal jacket" isn't true either. The jacket actually does not cover the base of the projectile.

True, but the contact surface of the bullet is indeed fully jacketed, as opposed to a "Dumdum" bullet which exposes a significant portion of the soft lead core of a military bullet.

At least one bullet manufacturer uses the term "totally metal jacketed" to describe its truly fully jacketed, lead exposure minimizing bullets.  A point about the non-jacketed base of an FMJ bullet: it can be finished with whatever desired level of smoothness and perpendicularity to the bullet's axis, but anything beyond simply keeping the lead all the way in the jacket adds cost.  GOOD target bullets have jackets that cover the base, offering a consistent and uniform base surface which helps minimize dispersion.  Conversely, the "known dispersion" feature of certain 7.62X51mm duplex rounds (and supposedly .50 BMG rounds) comes entirely from these qualities of the bullet's base.

Very cool guys. Thanks for the input.

I recall reading an old article in American Rifleman about civil war ammunition.  They had ball, minie ball, and buck and ball. The buck and ball were cartridges that contained buckshot and ball.  Nice mix.  The buck and ball were only to be used in smoothbore muskets.  A lot of infantryman prefered their smoothbore muskets because of the speed advantage loading and the ability for the buck and ball.  

Man the useless knowledge stored for years in my grey matter.

SoS