The 366 TKM was introduced in Russia around 2015 as a shotgun round. Gun rules in Russia are very restrictive with shotguns the easiest type of firearm to own. The 366 TKM is made up from 7.62×39 cases cut to 37,5mm and loaded with 9.3mm (.366in) bullets and used in smooth-bored, ‘Paradox’ rifling (on the last 140mm of the barrel to provide spin on the bullet), rebarreled AK rifles.