The Kuna is a delayed-blowback 9mm pistol/PCC/submachine gun developed by HS Produkt in Croatia and marketed int he US by Springfield Armory. Development on it began in 2020 as a commercial project, but probably also with an eye to military and law enforcement sales. The Croatian police are currently using quite old MP5 submachine guns that will need to be replaced soon, and having a domestic option seems like an obvious play for HS Produkt. They did win a trial for SMGs from the São Paulo police in Brazil, so it is off to a good start.

The Kuna (a type of marmot, as well as the name of Croatia's pre-Euro currency) was developed in .40 S&W, with a 9x19mm following. It uses a delayed blowback system similar to the HK roller-delay and the Stribog A3 system, and has completely ambidextrous controls. The US version has a 6" threaded barrel, pica tinny rear stock adapter with a folding arm brace, MP7-like backup iron sights, and proprietary magazines. The submachine gun version in Croatia uses a full-size folding stock, has a select-fire trigger (obviously), and also offers a 6.5" barrel with a trilug suppressor mount. Plans apparently exist for versions in .45ACP and 10mm Auto, as well as 12" carbines (and probably a 16" US carbine model).

Disclosure: This example was provided free of charge by Springfield Armory.