Custom Niji 5.1 Hi-Capa Gas Blowback Airsoft Pistol, Two-Tone

The Custom Niji 5.1 Hi-Capa is a competition-ready gas blowback pistol built from the ground up rather than assembled from a box. If you play speedsoft or want a sidearm you can actually tune, this is the kind of gun you start from instead of upgrading over several years.

The build. CNC aluminum slide and frame with stainless steel hammer internals. The parts come from a dozen specialists—Atlas Custom Works, Laylax, CowCow, TTI, Unicorn Airsoft, Dr. Black, Golden Eagle, Code 11—so you're getting individual components that each do their job well. The slide is lightweight for faster cycling, and the hammer and guide rod are stainless steel for durability.

What's in the box. You get the pistol, a 31-round magazine with a CowCow rainbow baseplate, and the manual. Gas and BBs are not included.

Velocity and field use. Rated 310–320 FPS on 0.20g BBs. That puts you safely inside most indoor CQB limits and works on outdoor fields that run tighter caps. As always, chrono with your own BBs before your first game—temperature and gas pressure both move the number.

Hi-Capa platform. Built on standard Tokyo Marui 5.1 geometry, so the aftermarket is deep. Recoil springs, blowback housings, inner barrels, and hop-up buckings are all interchangeable. If you want to tune it further, a high-flow recoil spring accelerates slide cycling, and a 6.01mm tightbore barrel with a high-degree bucking improves accuracy at distance.

Before you buy. This is a gas blowback pistol, so it runs on green gas. Mags are platform-specific, so spare 31-round Hi-Capa mags won't work on your M4 or AK.