This mod adjusts the dispersion values using empirical evidence that indicates that DCS dispersion is too large.
Some people claim that the gun dispersion in DCS is too high. An overview of the public empirical data used to come to that conclusion can be found in the link below and you can decide for yourself if this mod makes your sim more or less accurate to the real world.
Note that I did not compile the data, I only used it as a basis for creating this mod.
This mod is OVGME ready, or you can manually place shell_table.lua in DCS World\Scripts\Database\Weapons. Be sure to make a backup of the file in case you need to revert.