I have two quesitons and I want to avoid speculative answers. If you are a genuine military/law enforcement sniper, or have gotten your opinions from one, please respond! Question 1. What is the most reliable and most common tool for range estimation among snipers? Is it not true that lazer rangefinders can be detected and give away your position? Question 2. Are military snipers vulnerable to detection by infrared devices which spot body heat? If so, what measures do snipers use to defeat such devices?