There's an old adage around arrow speed stating, "a faster arrow is only going to make you miss faster". Arrow speed certainly takes a back seat to accuracy in the moment of truth, but in the same breath, arrow speed could make the difference in accuracy when judging yardage on the fly.
When it comes to increasing the lethality of your hunting arrow, arrow speed is not the sole factor but it does have crucial influence over your success as a bowhunter. Let's take a look at why arrow speed matters for deer hunters.
We need to start with obtainable expectations. Speed specifications on compound bows hold a meaningful place to marketing departments of bow manufacturers. Each year new models are released with over zealous speed specifications used to own bragging rights. Too often, uneducated consumers take the bait of speed ratings, IBO or ATA, released with new compound bows. In short, bow manufacturers do everything in their power to obtain the highest speed ratings possible.
IBO speed specifications are not replicable in real world use due to the lack of requirements. IBO speeds can be obtained with no draw length requirements, draw weights of 80lbs +/- .2lbs, total arrow weight of 5 grain per pound of draw weight, and zero accessories on the bow and/or string. Oftentimes manufacturers will go as far as using a specific chronograph at high elevations to enhance speed numbers.
ATA speed specifications came along due to the lack of standards used by IBO. ATA standards include meeting the follow criteria:
- 70 lbs of draw weight +/- .2lbs
- 30" draw length +/- 1/4"
- 350 grain arrow (TAW)
To make matters worse neither entity enforces their standards, leaving bow manufacturers to self govern the honesty of their speed tests. It's important for consumers to know this and expect inflated numbers on marketing specifications. In reality, IBO/ATA speeds are not obtainable in hunting situations thus bow hunters should not be overly caught up around speed specifications when comparing bows and expect arrows speeds slower than IBO/ATA ratings.
Arrow Speed Influence On Lethality Metrics
Understanding lethality metrics for the species of game you intend to hunt is paramount for all hunters. It's even more important to realize these metrics matter most downrange at the point of impact and not a few feet from your bow as most people measure them. To hunt whitetail deer with a bow, the vast majority of accomplished bowhunters use these lethality metrics as a bare minimum standard.
Understanding your personal hunting bow and arrow setup is a big part of knowing where you fall in line with those lethality metrics. So many variables have influence over your individual hunting setup and where you fall with KE and P. On the surface level variables such as arrow velocity and total arrow weight are the two biggest factors with arrow velocity being more important to KE and total arrow weight being more important to P.
Arrow velocity will be will be capped by your draw length, draw weight, and your specific bow model's cam system. In short, a longer draw length and/or higher draw weight will result in a faster arrow giving you an increase in both KE and P. The inverse is also true. Below are a couple general rules or statements on draw weight and draw length effect on arrow velocity
- On average, a 10 lb change in draw weight can affect arrow velocity by 20 FPS.
- On average, every inch of draw length can reflect a change of arrow velocity by 12.5 FPS.
There is also a valid argument that velocity deprivation happens at a faster rate with a lighter arrow. If you don't believe that to be true go outside and throw a ping pong ball and baseball with the same amount of force. So simply striving for additional arrow velocity and ignoring downrange lethality metrics will not provide favoring real life results.
Unlike arrow velocity, total arrow weight has no mechanical limit however it does have a bare minimum requirement. For ages, 5 grains per pound (GPP) of draw weight has been the industry standard minimum to safely shoot arrows from a compound bow. This is also the same standard IBO uses to reflect speed specifications of new compound bows.
Total arrow weight is very much a personal preference but recognize that it has a direct impact on arrow velocity, KE and P. The heavier the arrow the more P it will carry down range but it will carry less velocity. On average, every 5 grain increase of TAW will result in a velocity loss of no less than 1 FPS. As a result of less velocity, the arrow's trajectory will also suffer. However, there will be less KE, P, and velocity deprivation downrange, which results in a more efficient arrow. After reading that last line, one would like the heaviest possible arrow would be the answer. Wrong. While adding mass to increase your total arrow weight will make your lethality metrics climb, there is a point of diminished returns. See the example chart below
|350 grains||310 FPS||74.67 ft-lbs||.482 slugs|
|450 grains||290 FPS||84.02 ft-lbs +11%||.579 slugs +16.7%|
|550 grains||270 FPS||89.01 ft-lbs +5.6%||.659 slugs +12.1%|
|650 grains||250 FPS||90.19 ft-lbs +1.3%||.722 slugs +8.7%|
Being an extremist on either side of the mass or speed argument leaves people pigeon holed with limited abilities to exploit a wide range of shot opportunities. My personal approach around this topic as always been, get to the required lethality metrics with the best possible trajectory. A healthy balance of the best hunting arrow weight and velocity, as you can see in the chart above, gives you enough KE and P for any big game species in North America while maintaining the best possible trajectory.
Good Arrow Speeds For Deer Hunting
To beat a dead horse, arrow speed is a distance 3rd in priority behind accuracy and lethality metrics. In general, a good arrow speed for deer hunting is between 250 and 300 feet per second pending your TAW. This range of velocity with the correct arrow provides more than enough kinetic energy and momentum to effectively take down a deer while also maintaining accuracy at typical hunting distances. However, if you can get to the target with the required lethality metrics faster by all means do so.
Another factor to consider is the distances at which you are willing to shoot. At longer distances, arrow speed becomes even more important for maintaining accuracy and delivering enough kinetic energy to take down deer. If you plan to hunt at longer distances, you may want to consider a faster arrow speed to ensure flatter trajectory. Obtaining a flatter trajectory may not matter at the practice range when your target is static and you're shooting from known distances with ample time to execute the shot. It does matter in the moment of truth when that buck of a lifetime is chasing a doe, the yardage is an approximation within 5 yards, and you only have a few seconds to execute a shot at possibly your only opportunity. Trajectory matters in that moment and quite frankly it can be the only difference between shooting under that buck or hitting it in the vitals.
It's also worth noting that items outside of arrow speed and arrow weight heavily impact your arrow's lethality. The design of your broadheads, the quality of the arrow build, the length of your arrows, and your shooting technique are all important factors that can affect the effectiveness of your hunting setup. While it's some times fun to be a polarizing extremist, when it comes to maximizing your lethality as a bow hunter in a wide range of shot opportunities, playing at a happy medium will win every time.
Author: Chad Sylvester, Exodus Co-Found/Owner