Black Oak vs Blackjack Oak

[DixieReb31]

Is a Black Oak and a Blackjack Oak the same tree?
How large do Blackjack Oaks get?

[WDH]

Very different trees with very different leaf shapes.  Blackjack oak is usually scrubby but they can grow to over several feet in diameter although 12" to 14" is more typical. 

[stavebuyer]

Blackjack are most often scrubby and favor dry sites. Their leaves are waxy and more lobed than pointed. They often retain their dead limbs. Lots of ant nests in Blackjack oak.

[WDH]

Blackjack oak leaves are spatulate, widest at the tip. 

[DixieReb31]

I have two, what I call very large Blackjack oaks on my property.  I am familiar with the Blackjack just wasn't sure if a Black Oak was considered the same.  Now I know, it is not. 
The two Blackjack's I have are approx 60' tall. One has a circumference of 66", the other of 69".  Their crown in somewhat constricted due to growing on a tree line that has a large yellow pine next to one and a fair size Water Oak next to the other.  I was thinking maybe they are close to be champion trees.  I'm not sure how to measure for it though.

[WDH]

The Georgia Champion is 95" in circumference at DBH and 71' tall with a crown spread of 56'.  

[DixieReb31]

Oh well, still pretty good size for Blackjacks, I think.