Spring-Powered

Pulling the bolt back compresses a spring behind the piston directly, with no motor or gas valve involved; releasing the bolt lets the spring drive the piston forward and fire a single shot. Every shot is manually cocked, which caps rate of fire but also removes every source of electronic or gas-related failure.

This is the standard mechanism behind entry-level sniper platforms because a hand-cocked spring gun can run heavier springs, tighter tolerances and a longer stroke than an AEG gearbox comfortably manages, translating into higher muzzle energy and better range for a single well-placed shot rather than sustained fire.

Because there's no motor or gas system to fail, a spring gun is also the easiest platform to strip and rebuild at home with basic tools, which is part of why it's often recommended as a first internals-tuning project.