Combo of Leather Field Gun Recoil Pad + Shotgun Sling Leather for Ambidextrous

12GA Shell holder Shotgun Sling? :This sling is specially made for bullet models such as 12 Guage. Note that 20GA and 16GA are not available. 16GA Shell holder Shotgun Sling? :This sling is specially made for bullet models such as 16 Guage.