Arrow Speed & Hunting

Timberline - Jim Sherman
Arrow Speed & Hunting
By Jim Sherman
Jan 28, 2006, 06:55

The importance of arrow speed is greatly exaggerated for hunting. The fastest bow is not near as fast as the slowest Whitetail Deer. Accuracy is the most important aspect because the deer does not care how fast the arrow goes by it.

Speed comes at a price. Fast bows have features, like a low brace height, that makes them more difficult to shoot. There is a lot of difference between shooting with both feet placed perfect on level ground at a foam target and twisting around in a treestand trying to shoot over a limb at a live deer. Speed also means noise. A bow that shoots an arrow at 300 f.p.s. has to have a string that is also moving at least 300 f.p.s.

That string as well as the cables, limbs, and cams moving at high speed have to stop. That energy is absorbed by the bow and accessories and converted to vibration, which is sound. A bow string moving at 240 f.p.s. has less energy and of course less noise transferred to the bow.

The arrow is also a source of sound that most people don’t think about. You have probably noticed the difference in sound made by cars driving down a highway. The cars that are speeding make more noise because they are moving through the air faster. The air pressure and displacing the air makes noise.

The same is true of your arrows. The vanes and broadhead displace air. The air pressure against the vanes control the arrow but also make noise. The faster the arrow, the more noise. Get behind something near the target and listen to different speed arrows. You will notice a difference in noise, just like the speeding car. A Whitetail will hear that noise long before the arrow gets there unless you are shooting at the speed of sound, which is about 1000 f.p.s.

Most people will agree that a traditional broadhead won’t group well at speeds over 280 f.p.s. That forces you to use expandable broadheads, which have a number of disadvantages over fixed heads.

There have been a number of studies on arrow trajectory at different speeds. Easton did an interesting one where they compared arrows of different speeds and weights. They compared arrow impact 5 yards before and after the target.

In other words, if you shot at a deer that you think was 40 yards away and it was only 35 or was 45 yards, how far would you hit from where you held your sight pin.

Here is a comparison with a 220, 240, and 280 f.p.s. bows. These would pretty much represent the range of bows for most hunters and you can make the same comparison between bows at different speeds. The numbers under each yardage show how much you will be high 5 yards before and low 5 yards after that yardage.

SPEED	20 YD	30 YD	40 YD	50 YD	60 YD
220 f.p.s.	+2 - 4	+4 -5	+5 -7	+7 -9	+9 -11
240 f.p.s.	+2 -3	+3 -4	+5 -6	+6 -8	+8 -9
280 f.p.s.	+1 -2	+2 -3	+3 -5	+4 -6	+5 -6

The numbers are pretty insignificant at your typical hunting shots of 20 - 40 yards. A Whitetail Deer has about an 8” vertical kill zone, depending on the size of the animal and angle of shot. You can therefore shoot 4” below or above where you are aiming and still get a killing shot. At 30 yards only the 220 f.p.s. arrow will miss if you judge the shot 5 yards short. At 40 yards they all will miss if you judge it 5 yards short.