My dealer pointed me to these locally made quad rails.

Apex Machining Company: 2300 Apex Handguard System, Gator Grip, Rifle Length, Vertical Grip Slot

They look interesting, but I am unsure.

I want to mount my scope where it is half on/off the receiver and hand guard. The rails on these are mounted onto the slots. Will these be to tight enough tolerances compared to a unibody forearm? I don't ever want to loose a zero because of a screw becoming loose.

What do you guys think?