Purchased an Arcalock clamp for my bipod and installed Arcalock clamp and barrier stop. Clamp says it works with either Arcalock rail or RRS rail, MDT says rail is RRS compatible. with the three pins removed clamp won't even tightened down, with pins in it won't stay in place once pressure is applied. Even though clamp is supposed to work with either, do I need to get Arcalock rail, or is it possible MDT Arca rail built into chassis is out of spec? Thoughts?