How sharp does a broadhead need to be?

[S.Clancy]

I've thought about this for a long time but I don't know any calculations to back up my feelings. My personal opinion is pretty sharp, especially at the point of contact. "Scary" sharp broadheads are just that to me, scary. We hunt some remote places where a bad cut or puncture from falling on a quiver could end very badly. Plus, my broadheads are flying at 190+ mph (280+ fps) plenty fast enough to make pretty sharp into very, very sharp. Any mech or aerospace guys out there have data we can apply here?

 

[dtrkyman]

3 aspects to cutting, edge, velocity and pressure.

There is only one potential downfall to “sharp” which could be edge retention, some scary sharp edges are not durable at all.

Quality steel goes a long way, but I don’t think there is an exact answer to your question?


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[2blade]

I have a non scientific suggestion. Arteries are very similar to rubber bands, they both are elastic and stretch. So, stretch a rubber band in between your fingers and gently hit it with that broadhead, if the rubber band pops easily, you're good to go.

 

[Blockcaver]

Very sharp. Try cutting up an elk with a dull knife versus a sharp one. When you put a new blade on your Havalon it is incredible how easy it cuts versus one you have have cut up most of an elk with. Huge difference in effort and effectiveness. The rubber band test is a good one. Another is whether the Broadhead edge will bite on your thumbnail or if it just skids across the thumbnail.

Good luck.

 

[TC406]

What's everyone's go-to method for touching up broadheads?

 

[hawk45]

Getting stabbed with a dull knife isn't any better/worse than a sharp one. The same damage will be done.
That being said, a few swipes on a med/fine stone should get them back to "sharp" if they are very "dull".

 

[Billinsd]

Scary sharp!!!

 

[johnsd16]

For turkeys? Dull AF!

 

[jhm2023]

I use the rubber band test 2blade mentioned. I saw it on an episode of Bowhunter or in an IBEP course or something like that plenty of years ago. I always get clean pass throughs and dead critters so I think it's a good enough test. I'd rather decently sharp edge that will last as opposed to a razor edge that will get ruined after one shot.

 

[Bowhuntone]

We do a demonstration ever year at our hunter ed class with a 6" x 6" metal frame with rubber bands stretched both ways to make a cross hatch pattern. Then using a new cut on contact broadhead on a shaft push it thru the frame twice. The first time it slides thru with almost no resistance but on the second pass you can already start to see the rubber bands start to bend before it cuts thru. We do this to show the importance of a sharp broadhead. A sharp broadhead will improve your chances of a pass thru shot which normally causes increased blood loss with a better blood trail and increased chance of a short recovery.

 

[Btaylor]

As sharp as I can get them is what I carry. It seems the cleaner the cut, the more freely it bleeds. I dont know how you quantify that but in my experience it is true.

 

[Rich M]

Had a buddy on a quota hunt last year. We each shot 1. He used the arrow & broadhead he sighted in with - shot a wad of cardboard 4 or 5 times then a deer. Blood trail was just fine and easy to follow.

Shot placement is key, "sharpest" is nice but not necessary if the shot placement is right.

 

[Beendare]

FWIW, my Experience;
Not scientific...but I can relay some personal experiences from seeing a couple hundred animals die to arrows;

I used to do depredation for hogs....and have been in situations where I had to pull a arrow from one to shoot another. These were thin replaceable blade heads. There was a notice-able difference in cutting on the second animal even though the head felt pretty sharp.


I've seen the same poor performance on Elk with over the top mech heads and a couple of the short wide BH's where the cutting just wasn't good. One elk in particular I shot at 35 yds, money shot 1/3rd up behind the shoulder. The bull was caked in mud. That bull kept falling down, getting back up...a real head scratcher on a perfect double lung.

That BH was wedged in the offside rib cage so dull you couldn't cut your finger on the edge. Just bruised tissue, little bleeding. The only possibility was it dulled when compressing the thick mud caked hide on entry dulling the blades. Have you ever dragged a knife across the outside of and elk hide? /grin

So yeah, razor sharp is key. ...but also the heads ability to MAINTAIN ITS Sharpness through the animal. The design of the head matters, its mechanical advantage. Tapered heads retain edge sharpness better than over the top mech heads or short wide heads that have to plow a bit though hide, ribs- instead of sliding in. Cut on contact and quality steel also helps keep the BH sharp too.

All that, yet In most cases- this mechanical advantage isn't a big factor......you can use just about any BH on any arrow and on a good shot and you will be fine as there is so much energy in a modern compound. Its the heavier animals like Elk and big hogs that can cause problems with a less efficient BH. You really see the inefficiencies with BH design with Water Buff size critters.

...

 

[S.Clancy]

Very sharp. Try cutting up an elk with a dull knife versus a sharp one. When you put a new blade on your Havalon it is incredible how easy it cuts versus one you have have cut up most of an elk with. Huge difference in effort and effectiveness. The rubber band test is a good one. Another is whether the Broadhead edge will bite on your thumbnail or if it just skids across the thumbnail.

Good luck.

I understand what you're saying, but your arm isnt moving 280 fps when cutting up an elk. I also understand a broadhead being sharper is better. But at high velocity, at which point does sharpness have diminishing returns with penetration and cutting with increased risk to the shooter from accidental touching?

 

[Bowhuntone]

If your broadhead is sharp enough to ethically kill the animal you are hunting it will be sharp enough to cut you to the bone. Therefore knowing that you should have a plan and or items in your first aid kit to control or stop the bleeding to get to help or wait for help to arrive.

 

[Blockcaver]

I understand what you're saying, but your arm isnt moving 280 fps when cutting up an elk. I also understand a broadhead being sharper is better. But at high velocity, at which point does sharpness have diminishing returns with penetration and cutting with increased risk to the shooter from accidental touching?

Clancy, the NAP Spitfire practice blades that duplicate broadhead flight are totally dull, no edge ground in at all. I can shoot them into a Morrell Range bag target and they don't cut it up. Broadheads that are sharp certainly do. Would be no different shooting them into an animal. Dull is dull and won't cut as many arteries and veins, and take more effort to push through the hide and meat.

Ethically you want the heads as sharp as possible since a broadhead kills by cutting....not high velocity tissue damage like a rifle bullet...280 fps is slow....not 2,800 fps like a rifle. that creates massive hydraulic shock. Cutting causes loss of blood as well as creating a hole to the lungs/chest cavity so they collapse. A wound created by sharp blades bleeds more freely and takes longer to potentially clot up than one created by a dull blades.

There is a lot of good info in a bowhunter ed course on this. Take one, you may pick up a tip or two. And shoot sharp blades and be careful to not cut yourself! I've got a broadhead scar so know what I speak of! Good luck and shoot sharp heads!

 

[Trial153]

I have yet to see a head that is too sharp but i have seen plenty that werent sharp enough.

For example my knock on VPA/montec style three blade heads is that the angle prevents them from being scary sharp.

Along those lines the biggest draw for me to heads that is premium steel is the retention of the edge after the initial push through of the hair and hide. I seen and used head that a flat out dull after they been through one animal.

 

[Blockcaver]

I've always checked the sharpness of my blades after I retrieve an arrow post kill. Typically the blades are still sharp after passing through a critter unless damaged in rocks or possibly by bone. I checked 5 Spitfires this spring that killed black bears in BC (one for me, the rest for buddies). All had at least 2 or the 3 blades sharp enough to go hunting again, all were still straight and the heads spun well. That is my typical experience with them, as it was with Rocky Mt Titanium and Iron Heads. Another brand expandable had bent blades that were a lot duller on a sample of one from another fellow.

I shot a lot of Zwickeys (and Bear Razor heads for a bit when I started out) years ago. The Zwickeys survived the ride through the critter still sharp but not the Bear Razorheads as they were soft...and hard to get real sharp to start with.

 

[Wrench]

If dull broadheads were effective, they would have taken the market by storm. The creation and retention of the cutting edge is the expensive part.

 

[hodgeman]

The sharper the better. Speed doesn't make a difference. While you can probably still kill a deer with a "dull" arrow, the tissue damage will be greater with a sharp one.

Mammalian tissue is fairly elastic- a dull broad head will push it out of it's way while a sharper edge will slice it. A sharper edge will lose less energy than a dull one when penetrating a critter- giving you a better chance of pass-through...and a better blood trail.

There's just no compelling reason to not use the sharpest broad head you can manage.