That would depend on much more than the drugs bud. Your diet and training will be the deciding factor. I've seen people gain that much without the use of any steroid - though they were beginners. I usually do not respond to questions regarding weight-gain during a cycle as far as what is possible or what I did. I could tell someone that I lost 20lbs of fat and gained 5lbs of muscle on a certain 6 week cycle, and then everyone will assume it was the cycle and want to copy it, when it was a combination of several factors that made the change. I'd say its reasonable, but if bulk is goal why are you spending the money on Anavar when I'd assume that you'd reach your goal without it, though I see nothing wrong with adding it and it would make a nice stack - just not the cheapest way to reach your goal.