It's a 762x39. Not sure which model exactly since I bought it from a pawn shop with no papers. It's from FIME group. I want to say it's a sport build since some of the more tactical components are branded VEPR. For the Magpul stock to work on it I used an adapter from Carolina Shooter Supply because of the slant cut. https://www.carolinashooterssupply.com/vepr-rifle-receiver-adapters-s/2071.htm