Shotgun slugs vs. rifle projectiles
Some interesting ballistics. The calculation is that if each is discharged parallel to the ground, with the projectile ricocheting upon first impact, the shotgun slug will actually travel farther than the rifle bullet.
I do have some doubts... as the study notes, on a ricochet the projectile is generally flying end over end, and thus has high wind resistance. Their calculations indicate that the rifle bullet would go 1400 feet before ground impact, and then 3,400 feet on its ricochet, total distance 4,800 feet, The idea of a ricochet going upwards of a thousand yards seems much to my eye.