How should I track maintenance across my airguns and gear?

Keep one dated log per item: what was done, by whom, at what round count or fill count.

Reseals, regulator work, and o-ring changes matter at resale, and compressors and optics deserve the same treatment as the guns. The free Virtual Locker does this in one place: service sessions can cover several pieces at once (a bench day), each action logs against the specific gun, compressor, or scope, with photos, and your gear links to the guns it serves.