What factors effects penetration? [179 Days]

While playing around with the various arrow setups to decide whether the EFOC arrow builds are worth the effort and whether it will make an impact for shorter draws and lower poundage shooters, my thoughts drifted to other factors that would influence penetration in a typical hunting scenario. Most average archers (+/- 29” draw, about 70lbs) generates more than enough energy to get passthroughs on plains game. Its the Short Draw and Low Poundage (Ladies and Juniors) that needs every advantage they can get!

This is the list I came up with:

Broadhead Blade Angle
The sharper the angle of the broadhead, the better penetration you can expect from the head. this seems obvious, but because most broadheads are surgically sharp (well, at least bluddy sharp!) we tend to think that they will just cut.

It seems there is a sweet spot between angle and width… The closer you can get to 1:2 ratio the better. That means that a head that is about twice as long as it is wide will give you the best penetration for cutting diameter for weight & material thickness. 

If you can get a head that is strong enough without adding too much weight, a 1:3 will be even better, but with current materials, its not likely if you need to keep the arrow weight in mind as well. 

Less Blades
Three blades will penetrate better than four, and two blades will penetrate better than three. Extra drag of an extra blade cutting through flesh and bone will slow down the arrow faster. So if you want maximum speed and penetration, reduce the blades (at the cost of reducing the total cut)

Arrow Flight
An arrow arriving on target in a straight line, 90-degrees from the animal is more likely to use the maximum energy for penetration, as opposed to an arrow that arrives at a slight angle. So a bow that is not just tuned, but tuned to fit your abilities and shortcomings is a big bonus.

That is why I like bows with yokes. If your form is not perfect, you can at least get the bow to perform at its possible best next to your shortcomings. If you have the equipment and patience, any bow can be set up with top hats and shims. If you can, take the time!

Blade Finnish & Sharpening
Sharp blades cut better. Honed blades cut better and faster than serrated blades. Remember, here its about penetrating to the vitals, not maximum damage as it passes through. 

Thinner shafts
This is a debatable element, but my experience, limited as it may be, seems to suggest that I had a lot more pass throughs with thinner diameter arrows (GoldTip Pierce and Kinetics) – The logic behind it is simple thinner arrow leaves less surface for anything to grab hold on, less friction on the shaft. Although, to be fair, an animal is not a rubber butt, so I can not say that this is true without a shadow of a doubt.

Weight and FOC
A heavier arrow will penetrate better. No question. With all else being equal, a heavier arrow will go deeper than a lighter arrow. That said, on lower speeds, going too heavy simply is not practical. Go as heavy as you can practically go for the typical distances you are going to shoot. Adding the weight to the front of the arrow instead of the total arrow seems to be beneficial as well (flight and recovery, for sure, most probably also for penetration)

Total Improvement
Improving any one of these factors should improve your penetration, improving all of them will give you the best possible options for your effort, but this doesn’t mean its the best possible solution for you (for instance, a narrow sharp broadhead might give you better penetration, but your skill might require a wider cut to ensure you do pierce vitals. )

NOTE: I am assuming that as the archer is already lower on penetration and momentum, they will be hitting the vitals and not take risky shots or try and penetrate bone

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About Sean Nel 51 Articles
Sean Nel is a staff shooter for Archer's Edge South Africa, Beestinger, GoldTip, Sureloc and Health Matrix as well as an accredited Archery Instructor with the South African National Archery Association (SANAA)