Set up an hard elevation to value which fits you best and get use to it. My set up is 300 in most maps, 200 in cqb maps and 400 in medium range maps like Sniper Valley. Aim higher or lower depending on distance and situation in battle, i also have binded - + elevation function to additional mouse buttons for quick use. Trick with two quick shots is very helpful, if first one dont land, it serves as correction marker for second one. I’m not determined to aim only for heads so the trick works out for most times, of course if you use fast fireing rifle like M21.