I called mossberg the minute I received my MVP Predator (The 18.5 fluted, AR magazine,etc...) the CS told me exactly this "Only go to hand tight." Well my first thought was this guy just doesn't give a shit about today. I called back the next day spoke to another representative and was told the same thing.
I ended up using my fat wrench and meeting in the middle ground around 35 inch lbs, and everything seems okay...amazing the answers they give you when you call.