Diagnose AEG Compression and Air-Seal Problems

“100% air seal” is not a useful pass-or-fail promise for an assembled AEG. Diagnose the compression path in sections, then verify the completed replica with repeatable chronograph readings and normal feeding.

Test the piston group

Inspect the piston-head O-ring and cylinder surface. The piston should move without excessive drag and should create resistance during a controlled hand test. This check can identify a large leak, but it does not reproduce the complete firing cycle.

Check the fixed seals

Inspect the cylinder head and nozzle interface for damaged seals, poor seating or unintended movement. Confirm that the nozzle is the required length and profile for the assembled platform rather than selecting by length alone.

Check the chamber interface

The nozzle, bucking lips, chamber and tappet-plate timing must meet correctly during the cycle. A good static piston seal cannot compensate for a worn bucking, misaligned chamber or timing problem.

Verify after assembly

Use the same BB weight and chronograph setup for comparison. Look for repeatability, normal feeding and normal cycle behavior. Avoid promising a specific FPS increase from a seal change because the result depends on the full build.

For nozzle measurement and selection limits, read the POM air nozzle guide.