When my Wife and I visited her relatives in Jamtland, Sweden, they all had modern SAKO bolt action rifles for their Elg hunting (like our Moose in North America), but their shotguns were the Husqvarna underlever hammer guns with about a 7/8 inch wide carrying strap fixed to the swivel on the barrels with the length adjustable end through the swivel on the stock. The Elg were just "winter meat to them" but the trophy that they were really proud of and got them talking was the Capercaillie. Unfortunately I have no idea how they used the carrying strap on their shotguns. To me a "sling" is the multi-adjustable strap used by target shooters.