The Army's SWEAT model, which was developed by the Maneuver Center of Excellence (MCoE) at Ft. Benning, GA, is useful for understanding combat weapons as a ‘system of systems’- and for understanding the elements involved in establishing and maintaining zero. Within the SWEAT framework, the individual weapon ‘system’ is comprised of: Soldier (or shooter); Weapon; Enhancements (i.e. optics and mounts); Ammunition; and Training.
SWEAT AND ZERO
There’s obviously no magic in this model- and there wasn’t intended to be. But it serves as an excellent reminder that achieving effective hits on bad guys involves more than just a rifle or an optic; it requires proper calibration of each of the elements of a fairly complex system. This is important, particularly since we have a tendency to look at one or two components of the system (typically the gun and sights) in isolation.
Zero is the glue that holds the SWEAT elements together. It's about getting ALL of the components of SWEAT calibrated to each other. If any one of the components changes or moves, zero is lost… AND WE MISS.
So, what does SWEAT have to do with zero? A lot. Zero is traditionally defined as the alignment of sights so that point of aim (POA) equals mean point of impact (MPOI) at a specified distance. That’s technically true. Zero isn't just about sights, though. It's about getting ALL of the elements of SWEAT aligned and calibrated. A perfectly zeroed weapon, for example, will be suddenly un-zeroed if the shooter changes his/ her cheek weld. So, professionals must buy a high-quality, battle-proven optic and a solid mount- that’s incredibly important. But that’s not the end of our zero retention concerns.
Maintaining zero, which is foundational in terms of combat marksmanship and readiness, requires constant, deliberate checks. Confirming zero should happen as frequently as possible (i.e. once a week). Any changes or adjustments should: 1) be considered significant; and 2) always be recorded. This does two things. First, it gets the shooter into position on the rifle often enough, WITH FEEDBACK, to build consistency in the application of fundamentals. Second, it allows us to identify problems that could cause zero shifts on the range rather than in the fight.