How to Lead a Running Deer

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How to Lead a Running Deer

Category : Miscellaneous

There is always debate around the concept of shooting at running deer.  Some hunters don’t feel that it is an ethical shot choice.  They cite the higher propensity for wounding an animal as the reason why running shots are unsportsmanlike.  I don’t know if there is any statistical research on the subject, but I would contend that it comes down to knowing your own marksmanship abilities and making the right shot decisions in each individual scenario.  I’ve seen running deer that I have elected to not shoot at, and to the contrary,  I’ve shot at running deer on many occasions during my years of hunting.  I have probably cleanly missed more than I have hit, but I can say with certainty that I have wounded and lost far fewer running deer than deer I have shot at while they were standing still.

Some hunters aren’t the best judges of distance, and that includes both distance to the game and the distance they are actually “leading” the deer.  (Even fewer yet know the distance they should be leading a deer.)  But even if you know the deer is at 200 yards and you should lead it by 8-10 feet, unless you have considered how to judge what 8 feet in front of an animal at 200 yards looks like, your shots are still little more than guesswork. 

Its important to consider that there are a multitude of variables that can change how far to lead a deer.  For example, a deer that is not running perpendicular to you requires less of a lead than one that is running the same speed while passing you broadside.  For example, if a deer is running away from a hunter at a 45 degree angle, the lateral distance covered in relation to the hunter’s position would be almost 10 feet less, per second, than a deer running broadside at the same speed and distance.  So, to keep the examples simple, for the sake of illustration, we are going to limit this discussion to deer that are running perpendicular to the hunter at 100 yards. 

To complete this calculation you will need to know the velocity of your bullet and estimate the approximate speed the deer is running.  Realistically, whether the cartridge load you shoot has a velocity of 2800 fps or 3000 fps will affect the calculation at 100 yards very little.  Furthermore, as a bullet travels over distance, it loses velocity, but, again, this will not make a significant difference to the calculation at distances within 100 yards.

Whitetail deer can run at speeds up to 30 mph.  Its safe to assume that there are times, when deer are being pushed, that they run at full speed. However, it is more likely that the deer you shoot at will be clocking at something less than its maximum, especially before your first shot.  So assuming a deer is traveling at a good clip of 20 MPH, perpendicular to the hunter, at 100 yards, how far will the deer travel by the time the bullet reaches it? 

  1. First, you’ll need to convert that 20 miles per hour to feet per second so that the units your are using for the deer’s speed and the bullet’s speed are the same.  The quick way to do this is by typing into google “20 MPH in FPS”.  The result is 29.333 Feet Per Second.
  2.  Now calculate how long it will take your bullet to travel 100 yards (300 feet).  We will assume the bullet velocity is 2900 FPS, which is in the realm of average for most big game calibers.  Divide 300 by 2900 and you will have a very close approximation of the time it takes for your bullet to travel 100 yards; .103 seconds.  You can also find a ballistics chart for your caliber that will tell you the milliseconds of travel for varying distances.
  3. Now, multiply the distance a deer running at 20 MPH travels in 1 second (29.333) by .103 seconds.  The answer is 3.02 feet.  In other words, a deer running at 20 MPH will travel 3.02 feet in the time it takes a bullet moving at 2900 FPS to travel 100 yards.             
Ballistics Chart example for .270 Winchester, 130 gr. Silvertip bullet. (gundata.org)

Now that we know a deer running 100 yards away, at close to full speed, will cover about 3 feet before a bullet will reach them, we need to know how far to lead them to hit the vitals; and we need to determine some aiming points to reference in a fast shooting situation.  Here is what you should remember.

  1. An adult deer’s body, from the point of the shoulder to the tail, is typically between 3 feet and 4 feet long. 
  2. If you do a google image search for “running deer”, you will quickly see that its pretty safe to say that the length of the head and neck of an adult deer can be near half its body.  That means that when an adult deer is running, its nose is approximately 18 inches to 2 feet beyond the front of the shoulder.  From nose to tail, an adult deer extended in its stride will measure between 5-6 feet.
  3. Considering an adult deer with a body length of 4 feet, the vital area between the shoulder blade and the paunch will span about 12-18 inches behind the front line of the deer’s chest. 

So, given our calculations, which are based on some approximations regarding the deer’s estimated rate of travel, we can make a reasonable estimation on how to aim at a running deer, relative to our estimations of the body size of a mature whitetail.  When a deer is traveling 20 MPH at 100 yards, and your round is traveling at 2900 FPS, you will need to aim somewhere between the front of the deer’s chest and in line with its nose to connect with the vital region of the animal.  Variation occurs based on the individual body characteristics/proportions of the specific animal in your cross hairs, the exact rate of it’s travel, your bullet velocity and, of course, the angle the deer is running in relation to your position.  

Even though you can put mathematical calculation to a scenario for the sake of an article, it is easy to see how the actual situation in the field is impossible to measure in the split-second that a hunter typically has to make a decision to shoot or not; and then also decide just where to aim.  This is likely why many people feel that a running shot is less than ethical.  At times, in some situations, this is certainly true; but in other scenarios, or for hunters who are highly proficient with their firearm, running shots may be a necessary and effective means to filling a tag and they can be incredibly lethal if executed with careful precision. 

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