Genetics play a big role if we're estimating this.
Hormones do play a role. Unless you're achieving supraphysiological levels of test unnaturally, or you have clinically low levels, changing your test (naturally) won't really do much for you. And there's also other stuff that goes into it genetically speaking.
And recovery plays an important role too. Not to mention the split + diet + whether you're achieving progressive overload + if you're a newb or not.
I'd assume around 4-6 lbs of actual muscle would be realistic if you're a beginner to lifting.
If you're bulking, the amount of carbs you're eating can make the weight you gain on the scale seem even greater than how much muscle it is you've actually gained. This is due to the...