The scope should be mounted so that it is naturally in line with your eye when the rifle is shouldered. Generally speaking a lower mounted scope is easier to get behind, but stock design also plays a factor. If you have to un naturally hold your face off the stock or lower your face into the stock it can affect how well YOU shoot the rifle. Not the mechanical accuracy of the rifle.
On a hunting rifle lower mounted scopes mean the bullet is closer to the line of sight at close to moderate ranges which can make it easier to hit game at ranges between 50-150 yards. Since ANY sight is mounted above the bore the barrel will always be pointed slightly up at the muzzle in order for the bullet to rise up to your aiming point. The farther the sight above the bore, the more the bullet has to travel up to align with your sight picture.
Mounting the scope higher places it farther above the bore and increases the angle between the two. This means that the bullet will be farther above your line of sight at 50-150 yards which could result in shooting over a small target at closer ranges. At long ranges though this is an advantage.
On a hunting rifle lower mounted scopes mean the bullet is closer to the line of sight at close to moderate ranges which can make it easier to hit game at ranges between 50-150 yards. Since ANY sight is mounted above the bore the barrel will always be pointed slightly up at the muzzle in order for the bullet to rise up to your aiming point. The farther the sight above the bore, the more the bullet has to travel up to align with your sight picture.
Mounting the scope higher places it farther above the bore and increases the angle between the two. This means that the bullet will be farther above your line of sight at 50-150 yards which could result in shooting over a small target at closer ranges. At long ranges though this is an advantage.