Bristol Based Airsoft provides a technical walkthrough for upgrading the APFG XM7 airsoft rifle using a Crimson NPAS and a WaDy Hammer Spring. The process begins with the disassembly of the upper receiver, where the recoil spring and bolt carrier group are removed. The tech strongly suggests tossing the factory Phillips head screws into the nearest bin in favor of hex or Torx replacements, as the originals have a structural integrity comparable to wet noodles and are prone to rounding off.

The mid-section of the guide focuses on the internal nozzle components, which share a design lineage with the HK417. After a brief struggle with a stubborn gas tube screw that required some "creative" wiggling and a Dremel, the new NPAS is installed. He emphasizes correct orientation and generous lubrication, though he admits his own application of grease was perhaps enthusiastic enough to lubricate a small ocean liner.

The final steps involve swapping the hammer spring in the lower receiver, a task similar to standard AR platforms but with the added challenge of a "secret" tiny C-clip waiting to escape. Once the hammer is pinned back into place and the receivers are reunited, a quick function check ensures the nozzle retracts and the trigger actually does its job. With the upgrades complete, the rifle is ready for use, provided no "mystery parts" were left on the workbench.