In all honesty, I don't think most male porn stars are hung like a bull. It's takes a lot to impress me. What some people may consider big, I may consider average, or perhaps, small. For example, I don't think Tommy Lee has a big dick. I admit it he may above average in length, but the dude has not girth. So, in my books, his cock is very average.

Dicks I consider big (yes, a long dick without big girth is just long, skinny pencil to me).

Brian Pumper (big girth and nice length)
Mr. Marcus (big girth)
Julian (big girth and nice length, although seems less thick than Brian Pumper)

Brian Pumper has a bull dick. That's what I consider to be a hung stud. Ironically, he does not seem to get much attention for his dick. Go figure!