I Ignore that! WHY? Look at the arc of the bullet. i set up one rifle, 17 Rem, with HIGH or x high mounts. NOW when the bullet is rising and gets up to 1/2" below the line of sight, continues rising ABOVE the line of sight 1/2" and BY THE TIME, it drops one inch again to be 1/2 inch below line of sight- i can shoot a Coyote IN THE EYE holding dead on the pupil from- ARE YOU READY? from 75 yds to 200 YDS!! +/-. My 25 gr are 4230 fps. which helps, BUT, This would be absolutely & totally impossible with a lower mounted scope. IMPOSSIBLE!
That said- ok mirage is a good reason - for TARGET and prarie dog shooters- maybe pigs now too lol.
1) Good cheek weld is critical
2) a higher scope mount often makes "canting" more noticible. imo
3) Canting or tilting the rifle,, you "sent" the bullet on a trajectory left or right of intended and you could be holding dead nuts on- But...
4) a bubble level and USING it will surprise you how many times your badly canted.
5)***** Now - If SOMEONE can give me a good practicle theory or reason why why,why- a scope JUST ABSOLUTELY MUST BE mounted as close to the barrel as possible, other than the Marines did it or someone told me- id like to hear it. Other than what i've mentioned, and cheek weld is #1, a stock can always be mod'd to "raise" cheek weld.
*** I suppose in war time- "Billy don't be a hero," - "keep your head down" is a Good reason too. lol