Tighten to spec right away or tighten less than spec and then when set tighten all the way?I second JB weld. Tighten to specs with torque screwdriver.
Speaking specifically about one piece rails, unless the two mating surfaces are identical, meaning the top of the receiver and the mating surface of the rail .... you can actually twist / bend the rail into place by torquing the screws to spec.Tighten to spec right away or tighten less than spec and then when set tighten all the way?