Rangefinders may be used by military or law enforcement snipers as a means of finding the distance to the target in order to set up a "perfect shot". If range is not known before the first shot, it may be necessary to walk the rounds in on the target, such as using tracer ammunition or observing splashes. The laser rangefinder is not always the best option though, as it sends out a light source that may give away the rangefinder's position.
Army Test and Evaluation Command, Aberdeen Proving Ground Maryland (1969) Laser Rangefinders Ft. Belvoir Defense Technical Information Center, U.S. Army, Ft. Belvoir, Virginia, OCLC227620848 20 pages (early history of the use of lasers in rangefinders)
Gething, Michael J. (1993) Airborne Weapons: A Defence Handbook: A compilation of articles from Defence magazine over the last five years, charting the development of Airborne Weapons since 1987 Cardiff Publishing Company, Englewood, Colorado, ISBN 1-881289-11-7, 44 pages
Photographic and Imaging Manufacturers Association (1999) American national standard for photography (optics) : rangefinders and other focusing aids – performance specifications (revision and redesignation of "ANSI PH3.619-1988" as "ANSI/PIMA IT3.619-1998") American National Standards Institute, New York, OCLC41501265, 14 pages
Hicks, Roger and Schultz, Frances (2003) Rangefinder: Equipment, History, Techniques Guild of Master Craftsman, Lewes, United Kingdom, ISBN 1-86108-330-0