The growing interest in augmented reality applications has led to an in-depth look at the performance of head-mounted displays and their testing in numerous domains. Other devices for augmenting the real world with virtual information are presented less frequently and usually focus on the description of the device rather than on its performance analysis. This is the case of projected augmented reality, which, compared to head-worn AR displays, offers the advantages of being simultaneously accessible by multiple users whilst preserving user awareness of the environment and feeling of immersion. This work provides a general evaluation of a head-mounted projector for precision manual tasks and a detailed description of the experimental protocol applied for investigating spatial and temporal registration and their combination in a user test. The results show that the accuracy and latency of the device make it suitable for guiding precision tasks.