Understanding SAC Reference Points

Posted by Telluric Group on

The SAC provides two types of reference points, which we refer to as Correct Zero Position (CZP) and Personal Zero Position (PZP). Understanding each of those reference points and how they work is critical to using the collimator effectively. CZP is used before a shooter has established zero to speed up the initial zero process. PZP is used after zero has been established to confirm or return to zero.

M4 SAC Grid

Correct Zero Position (CZP)

CZP is located at coordinates ‘I,9’ on the SAC grid (at the point of the inverted triangle). CZP is zero for the average shooter on the specified weapon platform, with a specified ammunition type, at the specified range. Adjusting weapons to CZP will almost always get shooters on paper- and very close to zero- before ever firing a shot (shooters are typically within about 2 inches of zero on a 25m target). Note that, while it is possible to have an instructor or armorer adjust weapons to CZP in order to get shooters on paper, it is best to allow the shooter to complete the process. This ensures that the shooters’ individual characteristics (i.e. height, length of pull, eye relief, etc) are properly accounted for. Results will be much better if CZP is established by the actual shooter.

Each SAC has a user specified range and ammunition type that determine relative location of CZP on the grid. This only effects establishing CZP prior to initial zeroing. Adjustments can be made by the shooter to accommodate different zero ranges. The shooter simply moves point of aim slightly higher or lower on the SAC grid.

Collimator CZP provides a significant improvement over the capability offered by existing 'boresight' products. It is more accurate than any other boresight device AND faster and easier to use than most. The improved accuracy means fewer firing iterations to achieve than when other devices are used. The speed and ease-of-use advantage makes soldiers much more likely to use the SAC- and it saves valuable training time.

While extremely useful, CZP is only a secondary or ancillary capability of the SAC. Personal Zero Position (PZP), the primary type of reference point, provides a capability that no other product is able to deliver.

M4 SAC Grid

Personal Zero Position (PZP)

PZP is identified by noting point of aim (POA) on the SAC grid after zero has been established and confirmed using standard live fire procedures. Once PZP has been recorded, the shooter is able to quickly confirm zero and, when necessary, re-zero a weapon by simply adjusting POA to the recorded position. This is as accurate and dependable as conducting live fire confirmation (we still recommend live fire confirmation any time it is possible).

Different PZPs can be recorded for different distances, sights, types of ammo, altitudes, etc., enabling soldiers to build a ‘data book’ with PZP settings for a variety of sights and conditions.

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