U.S. M1887 Springfield Trapdoor and Krag Rifle Leather Sling U.S. model 1887 KRAG and SPRINGFIELD TRAPDOOR rifle sling. Top-grain leather sling with all brass fittings and copper rivets. Measures 64" (162cm) long and 1 3/8 (3.22cm) wide. Shipped from a USA company founded in 1981. Copied directly from an original sling in the IMA collection.