The Steyr MPi-69 is an Austrian 9×19 mm submachine gun developed by Steyr-Daimler-Puch and adopted by the Austrian Army in late 60s. Designed as a compact weapon for military and police use, it operates similarly like the Uzi and its earlier iteration of the SMG features a strange sling mounted charging handle (or charging handle mounted sling mount) and turns out it was a not a good idea.
All that changed with the MPi-81 version with changing away the charging handle part and other smaller production changes to make it more viable in the later years of the Cold War.
Model from bibibibirite (SketchFab) with thanks to Riceler and Markus for the support!