iirc you can brute force it by adjusting the gun settings which will in turn effect the AI weapons if they are using the same gun - it's a bit of a bug tbh but might work in your favour for this
GetEntityWeaponID: GetEntityWeaponID ( e ) -- Gets the WeaponID associated with the entity specified
SetWeaponDamage: SetWeaponDamage ( WeaponID, FireModeIndex, Value ) -- Sets damage value of weapon
SetWeaponAccuracy: SetWeaponAccuracy ( WeaponID, FireModeIndex, Value ) -- Sets accuracy value of weapon
SetWeaponReloadQuantity: SetWeaponReloadQuantity ( WeaponID, FireModeIndex, Value ) -- Sets reload quantity value of weapon
SetWeaponFireIterations: SetWeaponFireIterations ( WeaponID, FireModeIndex, Value ) -- Sets shot iterations value of weapon
SetWeaponRange: SetWeaponRange ( WeaponID, FireModeIndex, Value ) -- Sets range value of weapon