Most shooters chase elevation and windage. Fewer notice that the rifle is leaning a few degrees. That lean — cant — throws the shot off in both axes at once, and no amount of turret work will make it consistent.
When the reticle looks upright but the action is tilted, gravity and the line of sight no longer share a vertical plane. At short range the error is small. At 100 yards and beyond it becomes a group that opens left-low or right-low depending on which way the rifle was heeled. People then wind the turrets, “correct” one shot, and find the next one has gone the other way because the cant was not the same.
A rifle scope cannot see cant. It only shows the picture you have given it. The fix is mechanical: a level on the action or on the tube, and a mount that does not introduce its own twist. Sportsmatch make spirit-level kits for that reason — fixed and swing-out — so you can confirm the rifle is vertical before you fire the shot. On a hunting rifle that is the difference between a clean chest shot and a wounded animal. On the range it is the difference between a tight five-shot group and a mystery flyer you blame on the wind.
Mount height plays into this. A scope sat too high forces an awkward cheek weld. You roll the head, you roll the rifle and you have built cant into every shot. The right height is the lowest that clears the objective lens from the barrel and still lets you look through the centre of the optic with a repeatable head position. That is an accuracy choice, not a cosmetic one.
Quick detach (QD) rings add another test: they must return to the same exact position when you put the scope back on the rifle. A mount that needs re-zeroing after every removal is not maintaining the relationship and alignment between the scope and the rifle you paid good money for.
None of this replaces practice. It stops the hardware from inventing errors the shooter then tries to correct. If groups are opening and the ammunition is consistent, look at cant and cheek weld before you look at a new rifle scope. A level and true scope mount and a scope that sits where your face naturally fits on the stock will do more for accuracy than anything else.