Look up "Helical flight path."
This has been studied to death for over a hundred years, has a sound physics model, and was observed in doppler radar testing by the army. You need a 6 axis ballistic simulator to predict the flight path, all commercial ones that I know of are only 3 axis.
Dr. FW Mann first published findings on the phenomenon back in 1909, it as since been a subject firmly beat to death by physics students.
When a bullet leaves the muzzle tilted, precession can cause the bullet to engage in a helical flight path (a spiral, as it were). This flight path causes the bullet to "orbit" the true trajectory. In the end it either destabilizes or settles in, depending on many factors (including severity of the precession).
So yes, bullets can, and do, get "more accurate" down range, under certain circumstances.
It's become part of the standard accepted theory on exterior ballistics, and part of the reason why such emphasis is placed on creating "true" concentric bullets and precision reloading dies.