Just put a farrell 20 degree pic rail on my 7-08. For now, cheep 2 screw rings with round cross bolt. The rail slots are twice as wide as the ring cross bolts. Should I pull the bolt rings back in the slots or forward, prior to tightening? Just in case they would slip a little. I assume any cross bolt, weaver type mount rings will work in this rail, or is their a special type made for them? If slots are like 3/16" wide, are proper mounts made with a 3/16" square cross bolt? Thanks, Ron.