- The Newly Designed Caldwell Max Grip Sling Is Adjustable From 20" To 41" For Full Comfort Out On The Range Or The Trails. The Non-Slip Ergonomic Design Is Sure To Keep Your Firearm Secure While You're Out In The Wilderness. With Quick Detach Metal Sling Swivels, The New Max Grip Sling Is The Easiest And Quickest Way To Keep Your Firearm Secure.