As a rule of thumb, that is true; however, the AR-15 stock is on the same line as the top of the receiver versus a typical hunting rifle's stock which drops below the line of the top of the receiver. Thus, in order to have a comfortable cheek weld on an AR-15 stock, you will need to have your sights higher than you would with a typical hunting rifle. This is why the standard sights on an AR-15 are so high. There is a trade-off between how low to mount an optic and how comfortable you feel lining up behind the optic. If the optic is too low, you will feel like your face is fighting with the stock to see through the optic.