You don't "double your volume" in 3 months unless your starting point is ridiculously small and/or you're counting added fat. Contrary to what fitness magazines and supplement manufacturers like to pretend, the body's ability to synthesise protein to build muscle is fairly limited.
"Double" your strength, sure, in the sense that beginner gains due to improved coordination and better understanding of your actual limits means it's not uncommon to double or triple the weight you can lift in the first few months (I tripled most of mine in the first month I exercised - these days I'm lucky if I can increase my max by 2.5kg per month from starting points ranging from 90kg to ca. 200kg depending on lift; often the increase takes longer than a month by now).
"Double" your strength, sure, in the sense that beginner gains due to improved coordination and better understanding of your actual limits means it's not uncommon to double or triple the weight you can lift in the first few months (I tripled most of mine in the first month I exercised - these days I'm lucky if I can increase my max by 2.5kg per month from starting points ranging from 90kg to ca. 200kg depending on lift; often the increase takes longer than a month by now).