This article examines the operational effectiveness of 250-gram-class First-Person View (FPV) drones as a precision munition system in urban and semi-urban combat during the Russo-Ukrainian war, drawing on a structured synthesis of operational data released between February 2022 and December 2024. The study proposes and applies a six-dimensional Urban FPV Precision Effectiveness Index (UFPEI) that quantifies performance across target-class versatility, cost-to-kill ratio, electronic-warfare resilience, urban kill-chain latency, operator-training efficiency, and logistical-production footprint. Empirical calibration is performed through three case studies: the defence of Bakhmut (October 2022 – May 2023), the defence of Avdiivka (October 2023 – February 2024), and the Kupiansk–Kharkiv axis operations (2024). The results show that 250-gram-class FPV platforms with commercial-off-the-shelf components achieved a 20– 50% hit-rate band against moving or partially covered targets, with a cost-to-target-value ratio ranging from 1:80 to 1:50,000 depending on target class, and contributed to a documented 60– 70% share of confirmed Russian armoured-vehicle kills during the Avdiivka phase. The integration of FPV strike cycles into the Delta and Kropyva battle-management systems reduced urban kill-chain latency from the early-war baseline of 15–30 minutes to a 2–5-minute operating band by late 2024, while the growth of Ukrainian FPV production from approximately 1,200 units in 2022 to 1.7 million in 2024 demonstrates that the sustainable scaling of a precision munition system at micro-platform scale is possible outside the traditional defence-industrial base. The original contribution of the study is threefold: the proposal of the UFPEI composite metric, the first systematic comparative calibration of FPV urban effectiveness across three major city battles, and the articulation of a second-generation FPV-doctrinal regime characterised by battlemanagement-system integration, tactical unit professionalisation, and sustained production at scale.