a big thing about a vegitarian deit is that if you are relying on beans for protien, they lack alot of the essential amino acids that you need, they are not complete protiens, it may be possible to build an incredible body still, but by being a vegitarian you are limiting your possiblities to be alot bigger by quite an amount i would say. if you were to pump lots of
whey protien and have a wide viareity of different vegitarian sources of protien i am sure it is quite easily possible.