14.5, with a mid length gas system. I'd just suck it up and go with the FSC556. I was stupid, accidentally bought a flash hider for 30 bucks, had it pinned for another 30, and then had to cut it off and pay another 60 for a cheap comp and have that pinned. Should have just started with the FSC556, and it hides flash pretty well from what I hear, while still being MA compliant.
I started out with full length hand guards on mine and traded them with a buddy for his specter length ones. I'd rather have that weight up front be from my light, not my forearm. I do wish they made something about 1/2 inch longer than the specter so it fully covered the gas block, but I like my rifle.
I've since swapped out the butt stock
Mike