A technical guide by Stupid Airsoft showing the step-by-step installation of a hop-up bucking for the Raptor/ Lambda Defense SR2M gas blowback submachine gun. The demonstration involves replacing the factory-installed component with a Stalker bucking to compare the performance and contact platform design between the two parts.

The process begins with the disassembly of the receiver, which shares similarities with the takedown procedure of an AK-style platform. This involves removing the stock, dust cover, dual spring guide rods, and the bolt. Accessing the inner barrel assembly requires removing the handguard and punching out a pin that secures the trigger unit, followed by the removal of four external screws to separate the upper and lower receiver sections.

Once the internal assembly is accessible, the hop-up unit is extracted by loosening specific grub screws. The video shows the mechanical interaction between the hop arm, a small tension spring, and the bucking. After installing the new rubber component, the unit is reassembled by reversing the disassembly steps, ensuring that the internal springs and guide rods are properly seated before verifying the fire selector and trigger functionality.