Well, the head and face are total Lab, but the coloring...maybe APBT/AmStaff, or possibly Mastiff or American Bulldog. I know he's only 7 mos, but does he have that all-muscle tone body type?
Hmmm. That face looks very familiar. And so do those cute, round brown eyes!
Could he have a bit of catahoula in there somewhere? He's beautiful! I love that wonderful brindle color. He looks almost like a piece of varnished wood.
I don't see any bully breed in that dog whatsoever. I could venture as to say some sort of cur dog (Mountain cur mainly), but who knows. Brindle is not just a "pit bull" coloration. Many many many breeds come in that color pattern.