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Outdoor life broadhead test

Yeah the heavy vs light debate is so oversimplified. So is fast vs slow.

I set a a chronograph up at 40 yards and shot arrows from 430gr up to 630gr. Difference coming off the bow was about 40fps but that 430 gr arrow slowed down a whole lot more out at 40. They were only like 15-20fps different at 40. So what does fast mean? What is slow?
At the distance I shoot whitetail I am confident in my trajectory and I know I will have way more momentum with a heavier setup. If I was shooting out west I would go with a lighter and faster setup to give me a better trajectory at longer range. But even then I would experiment with weight and speed and trajectory at target to maximize mass while getting the trajectory I want.

I do the same thing with bullets.

I've posted this before, but a factor that may be important (in physics) for killing deer is time to target.

I'm also interested in a deeper dive on the effects of friction on archery shots, where most of the cited physics quotes laws of fluid dynamics.


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I've posted this before, but a factor that may be important (in physics) for killing deer is time to target.

I'm also interested in a deeper dive on the effects of friction on archery shots, where most of the cited physics quotes laws of fluid dynamics.


View attachment 72515

those drop tables often don't tell the full story for me

they often are for an arrow shot perfectly horizontally

but an arrow shot from a bow is dropping from the apex of its flight which is about halfway between the shooter and target, if firing a pin for that yardage

so, on a 30 yard shot, a 250 and 300 fps arrow is more a drop from around 15 yards and then the 300 fps arrow gets there faster so less drop time but it isn't gaining that advantage over the entire 30 yards...also the 250 fps arrow will rise higher at 15 yards which is kind of a bad thing but will mean that in the drop test from 15 yards in to the target that this tends to offset the faster bow's advantage

having said that, i went from a 290 fps setup to 265 fps two years ago, and i won't go any slower than 260 fps ever and would like closer to my old speeds....i'll probably go with a faster bow next time
 
I've posted this before, but a factor that may be important (in physics) for killing deer is time to target.

I'm also interested in a deeper dive on the effects of friction on archery shots, where most of the cited physics quotes laws of fluid dynamics.


View attachment 72515

Time on target is important, especially for white tails. I won’t shoot beyond 30 yards because of that. Most of my shots are under 20.

Momentum and kinetic energy don’t really have anything to do with fluid dynamics. Arrow flight does but fluid dynamics applies to liquids and gases (air).
 
Time on target is important, especially for white tails. I won’t shoot beyond 30 yards because of that. Most of my shots are under 20.

Momentum and kinetic energy don’t really have anything to do with fluid dynamics. Arrow flight does but fluid dynamics applies to liquids and gases (air).

Dr. Ashby makes a case for penetration citing pretty much exclusively principals of Bernoulli.

But, to your point, fluid dynamics is why your faster (and lighter) arrow slowed down more at from 0-40yds.
 
those drop tables often don't tell the full story for me

they often are for an arrow shot perfectly horizontally

but an arrow shot from a bow is dropping from the apex of its flight which is about halfway between the shooter and target, if firing a pin for that yardage

so, on a 30 yard shot, a 250 and 300 fps arrow is more a drop from around 15 yards and then the 300 fps arrow gets there faster so less drop time but it isn't gaining that advantage over the entire 30 yards...also the 250 fps arrow will rise higher at 15 yards which is kind of a bad thing but will mean that in the drop test from 15 yards in to the target that this tends to offset the faster bow's advantage

having said that, i went from a 290 fps setup to 265 fps two years ago, and i won't go any slower than 260 fps ever and would like closer to my old speeds....i'll probably go with a faster bow next time

This isn't a trajectory drop table. It's how far a deer can drop in reaction to the first instance of warning from noise based on speed of sound at the impulse of the shot to when the arrow arrives at the target at a specified speed.
 
Dr. Ashby makes a case for penetration citing pretty much exclusively principals of Bernoulli.

But, to your point, fluid dynamics is why your faster (and lighter) arrow slowed down more at from 0-40yds.

Yeah I think some of Ashby’s science was a bit oversimplified at times and just wrong at other times. He is a Dr but of dentistry. :). Don’t know how much aerodynamics or physics he had to take to prep for dentistry school. I do value his documentation of countless examples though.
 
Yeah I think some of Ashby’s science was a bit oversimplified at times and just wrong at other times. He is a Dr but of dentistry. :). Don’t know how much aerodynamics or physics he had to take to prep for dentistry school. I do value his documentation of countless examples though.

I value the documentation as well, but it seems somewhat specific and somewhat old. Not to say I disagree with many of his conclusions either, just a bit curious of some of it.
 
Hay man to each his own. If a pass thru is the goal and faster arrow for me does that I would be insane to shoot a slower arrow. Pretty simple.
Just remember not everyone is able to shoot 70 pounds and a 30+ inch draw. You found what works for you and that's great. I'll never be able to achieve the speeds you can and I couldn't get passthroughs even without shooting mechanicals. Going slower/heavier changed that. It's not one size fits all and that's alright.
 
Just remember not everyone is able to shoot 70 pounds and a 30+ inch draw. You found what works for you and that's great. I'll never be able to achieve the speeds you can and I couldn't get passthroughs even without shooting mechanicals. Going slower/heavier changed that. It's not one size fits all and that's alright.
I agree. Being able to shoot 70 with a 29.5 draw with a 457 gr. arrow is my personal perfection. Like you said some can’t draw 70 and that is totally ok. Finding the sweet spot in your setup is what matters. We all want a pass through and can achieve it with different numbers
 
I agree. Being able to shoot 70 with a 29.5 draw with a 457 gr. arrow is my personal perfection. Like you said some can’t draw 70 and that is totally ok. Finding the sweet spot in your setup is what matters. We all want a pass through and can achieve it with different numbers
I know it's not the norm but I've seen my father in law get a pass thru on whitetail doe with his 45lb recurve shooting a light fast arrow. Was a cut on contact small broadhead.cant remember the brand. I think that was the only pass thru he had with that set up. He does kill deer every year with it though . He is a very good tracker lol
 
Ballistic gel is not even remotely a good predictor of penetration on an animal with bone, muscle, sinew, vessels etc. for the same reason my foam 3d targets aren’t. The Lusk videos are fun but I don’t know that they are helpful for predicting penetration. There is an argument that they are somewhat good at showing edge retention though I don’t know how predictive metal plates and cement blocks are?
I actually like the cindedblock test. Shooting from a tree, the arrows often get buried in the ground, which does contain gravel in lot of places. At least Swhackers get toasted pretty easily.
 
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