Dispersion modifier on some sights is equal or greater than the dispersion of the weapon itself, resulting in zero dispersion when attached.
Mosin with PU scope = 0 dispersion
VSD with PSO-1 scope = 0 dispersion
Tundra with hunting scope = 0 dispersion
CR527 with hunting scope = 0 dispersion
Blaze with hunting scope = 0 dispersion
Sporter with hunting scope = 0 dispersion
In old versions of DayZ these scopes had appropriate dispersion modifiers so the weapons still had a believable dispersion.
There is not a good reason for most of the above examples to exist, as most have 0.001 dispersion with optic of -0.001 dispersion (hunting scope, PU optic) that sees little/no use on weapons not listed.
No gun in real life has zero dispersion!
Dispersionmodifier/dispersion on these weapons and optics should be changed to appropriate values.