Any avid hunter will tell you that the ability to correctly range your target is absolutely critical to proper shot placement due to the effects of gravity on any projectile as it travels toward its target.
For example,when shooting at ranges of 200 yards or less, a common practice is to zero a rifle’s scope at 100 yards and then hold the crosshairs a given number of inches low at ranges less than 100 yards and a given number of inches high at ranges greater than 100 yards depending on the published ballistics of a given round.
Another alternative that some hunters prefer to employ is to use one of the new, ultra fast, “mash-em-flat magnum” cartridges such as the Remington .300 Ultra Mag because these ultra fast cartridges have a significantly flatter trajectory than their slower cousins and thus, they are better able to compensate for miscalculations in range estimation. However, there is a way to use the reticle of your scope to accurately range a target ( if the usual rangefinder can`t do the job) as I will explain in the following article.
How To Measure Distance To Your Target Accurately
To begin with, first be aware that there is a way to use a duplex reticle to range your target but, a far more sophisticated method is to use a Mil Dot reticle which consists of a pair of crosshairs with round “milliradian” dots placed at equal intervals along the length of each crosshair.
Using this method, a circle is first divided into 6,400 equal parts such that one mil-radian equals 1/6400th of a circle. For the average hunter, this simply means than one mil-radian equals 3.6 inches at 100 yards, 7.2 inches at 200 yards, and 36 inches at 1,000 yards.
In order to accurately range the target, we also need to know the approximate size of the target. Then, based upon the size of a given target, a mathematical formula is employed such that the height/width is multiplied by 27.78 and then divided by the number of number of “mils” the target subtends.
For instance, if a hunter were aiming at a deer with a body that measures 18 inches in height, then he would place the horizontal crosshair on either the edge of the deer’s back or the edge of its belly and then note the number of mil dots required to bracket the deer from back to brisket. Then, he would multiply the height of the deer’s body (in this case 18 inches) by 27.78. Thus, 18 multiplied by 27.78 equals 500.04.
Then, that product is divided by the number of mils the target subtends. Thus, if the target is bracketed by 1 mil, then it is 500.04 yards out and, if it is bracketed by 1.5 mils, then the target is 333.36 yards out and, if it is bracketed by 2 mils, then it is 250.02 yards out.
However, because most hunters have far more important things on their minds than memorizing mil dot ranges, it is wise to make these calculations at home using a calculator based upon the average size of the chest cavity of the species you intend to hunt and then write them down on a small card and have the card laminated to waterproof it.
That way, once the target is acquired, all the hunter has to do is note the number of mil dots required to bracket the game animal and then, he can consult his range card to accurately determine the range. Then, once the correct range is determined, the hunter can use published ballistics tables for the cartridge that he is using to accurately determine the correct amount of “holdunder” or “holdover” depending on the range at which the scope is “zeroed”.