Newling Bulking Question

I’m bulking right now because I’m tired of keeping my weight down for a weight-class in grappling (which I am on hiatus from). I am doing a strength-phase right now which will probably be about 6 weeks, possibly more before I take a light week.

Not that I am complaining, but I am wondering, why is it that the scale is not really moving up too much and yet my measurements in calves, thighs etc are creeping up 1/8th and 1/4 inches at a time ?

I know it’s possible that you can gain muscle and shed fat simulatenously, but it can’t be this easy. I am saying I refuse to believe I am genetically gifted. Is this the oft-mentioned ‘newbie gains’ in effect ? Will this wonderous effect stop soon ?