The couple hit up Bullets and Burgers in Vegas Saturday -- the day he turned 27 -- and they were loaded for bear. Kylie fired a Glock 17 and MP5K, while Tyga took aim with a gold .50 caliber Desert Eagle and an M16.
The firepower was so intense ... both needed someone to hold them up from the recoil.
After the bullets, they jumped on what's tabbed as the world's largest monster truck. Add burgers and fries, and that's a birthday with some serious kick.