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How to Achieve Ultimate Penetration

By on October 19, 2022 0

I believe the broadhead design is the most important factor in arrow penetration. A streamlined, pointed head like the G5 Striker V2 will maximize your arrow’s kinetic energy at impact.

A few days before writing this, I had the pleasure of chatting with TV celebrity Kristy Titus at the Total Archery Challenge event in Park City, Utah. Kristy has an upcoming elk hunt and wanted to make sure her new 58-pound Bear Refine compound was set up for deep penetration.

We looked at her setup, did some math, and decided that any elk within 60 yards would be in big trouble…Kristy is a great shooter.

Serious archers like Kristy leave nothing to chance when it comes to their equipment. They analyze every aspect, make the necessary adjustments and go on the hunt with confidence.

Bowhunters shooting heavyweight setups tend not to worry about arrow penetration for larger game. This is not necessarily true. However, female bowhunters like Kristy Titus usually think about it more because their draw weights tend to be lower, their arrows lighter, and as a result their kinetic energy is often marginal. But no matter what bow and arrow you shoot, there are factors that can enhance or completely ruin deep penetration with creatures like caribou, elk, moose, mature black bears, wild boar, and a host of of massive African species.

First, let me say that there is not too much arrow penetration. The more you can get, the better. Deep penetration improves the chances of an exit hole for greater blood loss to the ground. Even if your arrow doesn’t go completely through, every inch of broadhead travel means more tissue damage and faster destruction. The old notion that an arrow must stay inside a creature is superimposed. Complete passages are the best.

For an elk-sized animal (500-800 pounds), I think the arrow energy at close range should be 50 foot-pounds or more. Kristy’s setup shoots a 330 grain arrow at 263 fps, producing 50.7 ft-lbs. of energy. With its arrow slowing down by about two fps per 10 yards of forward travel, at 60 yards the shaft would still be around 46 foot-pounds. – enough to drill an elk deep, if other factors are optimal. Let’s discuss these factors.

One thing that I believe is overrated in penetration is shaft diameter. Arrow makers often tout their lean shafts as superior penetrators, but in my experience this is rarely true in an animal – unless the arrow is impacting heavy bone. Most factory arrow penetration tests are done in artificial, sticky substances like ballistic gelatin. These have nothing in common with animal flesh and give false results.

With most arrow shots on game, the projectile passes through ribs or soft tissue. The wide tip cuts a hole much larger than the handle, and once that cut is made the handle slides out behind with very little friction. Shaft diameter – large or small – is not a factor. Blood, grease and other slippery body materials lubricate the wide head channel and reduce shaft friction to almost zero.

Whether it’s a chunky 2413 aluminum shaft or a skinny 5mm carbon shaft with only two-thirds of the outer diameter, both will penetrate about the same with the same wide tip. Penetration tests through leather and animal carcasses proved it to me beyond a shadow of a doubt.

Small diameter arrows certainly penetrate better through bone, such as the edge of a shoulder blade, because the bone clamps onto a shank. Small diameter trees also track better in crosswinds. But in most cases, the difference in animal penetration is exaggerated.

One of the most important variables in arrow penetration is the quality of their flight. You don’t have to be a rocket scientist to figure this out. A clean-flying arrow puts all of its power directly behind the wide point in flight. At impact, that power pushes straight forward to sink the broadhead deep. In comparison, a wobbling arrow loses energy by swinging back and forth in flight. On impact, even more energy is returned to one side.

Make sure your arrows cut bullet holes through stretched paper at a distance of 10 or 12 feet. If they tear the paper up, down, left, or right, you need to adjust your bow until those poor paper tears go away. Then – and only then – will your hunting arrows achieve maximum penetration into game.

More than anything else, the broadhead design will make or break penetration.

Think about it. If you attached a rubber blunt to your arrow, it would bounce off an elk. If you attached a streamlined, razor-sharp head with two narrow blades and a knife-like tip, it would completely slice through an edged elk. Same arrow, same kinetic energy, but very different results.

That said, it’s no surprise that Native Americans pocketed deer, elk, and other creatures with arrows that had small, sharp, streamlined, two-edged stone tips. Their bows were rudimentary and positively puny, with estimated arrow speeds under 150 fps and kinetic energy under 25 foot-pounds. Yet fine arrowheads made the difference and fed primitive peoples for thousands of years.

Most bowhunters use broad points with patterns somewhere between a rubber blunt and a thin two-edged knife. For deer-sized game, three- or four-bladed heads and fairly large nose sections will penetrate well. So will mechanical fighter heads that open on impact which quickly expand and dig a huge hole. But for animals like elk, broadheads must be carefully selected.

Of course, mechanical heads like the ones offered by G5, Rage, and others will slice a giant wound channel through a whitetail deer. From a mighty 70 or 80 pound compound bow these same heads could do the job on a wide sided elk but all else being equal a fixed two or three blade head with a tapered nose will penetrate much better on bigger game. of all arc configurations.

Your standard stag rig isn’t always enough for bigger creatures like this bull elk.

Bowhunters often wonder what the best tip weight is. Weight isn’t much of a factor in animal penetration, but the balance of forward-center (FOC) arrows certainly affects flat trajectory and pinpoint accuracy. For the best of both worlds, it is wise to shoot hunting arrows with a balance of 10-15% forward weight. Testing by Easton and others has proven it to be an excellent compromise between flat trajectory and consistent accuracy.

For a girl like Kristy, with very light arrows, a 100 grain wide tip gives good FOC balance. With heavier arrows in the 450-550 grain range, 125 grain heads are required for good FOC

Deep arrow penetration in very large game is a must. Use a bow/arrow configuration that produces at least 50 ft-lbs. point blank arrow energy. Set for the perfect arrow flight, then select a low-friction, contoured broad tip. With these three factors, you could pull your arrow out of a tree after it went through an elk!

Arrow Energy Calculation

To calculate the kinetic energy of your arrow, you need to know its velocity (speed) and its weight.

Most archery stores have a chronograph that you can use to determine speed. Any grain scale will give you an exact arrow weight – make sure your chosen arrowhead is attached.

From there, a simple formula reveals the precise energy: Velocity (fps) x Velocity (fps) x Weight (grs.) divided by 450 240 equals Energy (ft.-lbs.). For example, let’s say you are shooting 500 grain arrows at 250 fps. Using this formula, 250 x 250 x 500 divided by 450,240 equals 62.47 ft-lbs. With perfect arrow flight and a proper hunting head, you’ll probably shoot completely through an elk or moose.

To increase arrow energy, increase bow power and/or increase arrow weight. Arrow speed and flat trajectory will decrease with a heavier arrow, but kinetic foot-pounds. will always increase.

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