Waldo Dynamics Crimson NPAS for VFC / APFG / Maruyama

An NPAS (Negative Pressure Adjustment System) is what lets you tune a GBBR's energy output through the same flexibility a properly-built HPA system offers. The principle is simple: restrict the airflow inside the nozzle to reduce the gas energy reaching the BB, and you can dial output from below 1 joule all the way to 2 joules and beyond depending on barrel and BB weight. What makes the Crimson NPAS different from other NPAS products on the market is the internal bore geometry.

Waldo's design uses a tighter internal bore than the established NPAS units. The practical effect is shot-to-shot consistency at the 0.9-1.2 joule range that UK skirmish sites operate within — exactly where most players need to tune their rifles to chrono-pass cleanly. Other NPAS units can struggle with shot variance at this output level; the Crimson NPAS holds tighter groupings on the chrono day after day. The tighter bore doesn't prevent reaching higher energy outputs either — verified past 2 joules on standard barrel lengths with 0.36g BBs.

Reports from testers also suggest improved gas efficiency over stock nozzles — Waldo's testing confirms the trend, though individual results will vary with platform and gas. The crimson red nylon polymer construction is stronger than aluminium NPAS alternatives in the high-impact areas, and the distinctive colour means you can identify the upgrade at a glance during maintenance. Compatible with a vast range of platforms across the VFC, APFG and Maruyama ecosystems — see the spec table for the full list.

Specifications