RPK 26cm Russian Prison Knife Black Hollow ground vintage automatic knife

RPK 26cm Russian Prison Knife Black Hollow ground vintage automatic knife most likely made in 1960s or 70s by inmates of USSR prisons to be sold, traded, given as gifts/bribes by prison officials. The knife measures 25.6cm (10.1 inches) open and 5 3/8 inches closed with steel liners, button and hollow ground blade. The hollow ground straight back blade looks to be full and shiny with light scratches and no markings. The black sculptured synthetic scales are very attractive and in great condition. The knife works well with blade tip deep and centered in the channel, strong smooth snap and great lockup with just a hint of movement and does not rattle if shaken when open. Leaf spring fired. EX condition.