I have been using the original ACE Rail Sling Mounts (SMR) for years. I have always appreciated the simplicity of the design which is a simple sling loop, milled from a single block of aluminum, and clamped to the rail with a single bolt. Now ACE is offering a new version of the Rail Sling Mount with a QD sling swivel socket integrated into the design. This simple change adds a considerable amount of versatility and redundancy that will be welcomed by anyone who has had a QD swivel fail at a bad time.
These are not currently available at the ACE website. The are available from J&T Distributing.