This study presents an experimental testing regime conducted on filament wound composite pressure vessels (CPVs) made up of an asymmetric and unbalanced layup (chopped strand mat (CSM)/−82.7 deg/±54.3 deg) and subject to an internal pressure. Polyester reinforced with e-glass CSM and direct roving was used. The mechanical properties of the different lamina used in the test specimens were identified through a series of standardized tests. The evolution of strain and volume changes with respect to the applied pressure loading were recorded. The results also present a characterization of identifiable first-ply failure (FPF) loads based on strain evolution and volume changes, and monitors when ultimate failure occurs.