How much muscle can a lacto-ovo vegetarian build?

From what I read, a natural athlete following a typical bodybuilding diet with supplementation can build about 30 pounds of muscle. I'm guessing that a vegetarian that doesn't eat a lot of animal products/protein can't build that without supplementation, but I would like to know how much they could actually build. My goal is pretty much about 15 pounds of muscle and I was wondering if that's doable.

Should be equally do-able not matter your sources of nutrients. Amino acids (e.g. proteins) from plants and animals is mostly the same to the body. Should find plant sources more readily absorb-able and require less energy from your body to 'process'.

I think the difference is it can take a bit more thought going plant-based for all you needs to grow kickass muscles (possilbe without any supplements too!) than being a more meat/potatoes/salad eater without much planning. (I think more margin for errors being carnivore, plant-based complete nutrition isn't hard, just takes some thought/experimentation).