Chrono (Chronograph Check)

A player fires several shots through a chronograph — a device that measures BB velocity via light sensors — usually with the field's own test ammo to remove any doubt about BB quality or weight affecting the reading, and the average or peak reading is checked against the day's FPS or joule limit for that gun's role.

Guns that fail are turned down, capped with a limiter, or excluded from play until fixed — no field lets an over-powered gun onto the field regardless of intent. Because joule creep and spring settling can shift a reading over a season, most fields chrono every gun at the start of every game day rather than trusting a past pass.

Arriving early specifically to chrono before the queue builds is a habit most regular players develop quickly, since a long line right before the first game of the day is one of the most predictable bottlenecks at any field.