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Mechanical broadheads are junk

Blan37

Blan37

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I had to Google it

"An object's change in momentum is equal to its impulse. Impulse is a quantity of force times the time interval. Impulse is not equal to momentum itself; rather, it's the increase or decrease of an object's momentum."

So I think it means no matter how much energy you throw at a target, if the force times the mass divided by the cross sectional area is equal to or greater than....

Ah fug it.... Lol


 
Milo

Milo

Tatonka guide.
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"J" said:
The bigger the arrow the more energy it carries Eric???
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Sort of if you mean weight. Heavier Weight generally means larger cross sectional area and the more area, the more energy it can transfer before movement. Kinetic energy is a measure of instantaneous energy measurement, there is no force measurement unless you change it to momentum, which is the proper units of a force measurement.
 
hickslawns

hickslawns

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giles said:
I'm giving my phone the puppy look...I'm all sorts of confused now. Lol
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Shoot your arrow into a target. Then shoot someone's heavy arrows into the target. See which one goes in farther. That will give you a nice visual.
 
rsmith

rsmith

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Let's not forget about FOC though. A Easton Hexx with a 75g brass instert and 100g head cut at 28 inches will out penetrate a Easton FMJ cut to the same length and same head due to where the energy is being stored if you will. Even though the HEXX may weigh less it will most likely out penetrate the FMJ due to greater FOC and the ability to transfer the energy the bow produces more efficiently to the front of the arrow and maintain the energy in the front. At least that's what I got from my readings over time on benefits of higher FOC

 
hickslawns

hickslawns

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giles said:
"FOC"? I can think of a few acro's for that...but was told to behave. Lol. Seriously though, what does it stand for?
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Front of center. Has to do with the balance of the arrow and forward weight. Here is an excerpt from the "Hunters Friend" website:

If you've ever played a friendly game of darts, you've surely noticed that the dart is designed so that it's heavy in the front, and light in the back. If the dart were weighted the opposite way, with the tail being heavier than the tip, it would literally spin around and hit the target tail-first. Obviously the ballistics of a dart and an arrow are a bit different, but the underlying concept is similar. A projectile's flight is most stable when most of the projectile's mass is positioned Front (or Forward) of Center [FOC]. As such, an arrow should be heavier in the front than in the back. But how much? Where's the "perfect" balance point?
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Milo

Milo

Tatonka guide.
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Don't mistake target penetration of two separate (types) arrows for real world results. Many things depend on arrow make up and forces to stop it
 
Curran

Curran

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And... after you figure all the math, analyze various arrow builds and decide what is the right build for your bow it still comes down to shot placement. : )


 
Jackalope

Jackalope

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Another huge factor in an arrow delivering it's full force potential is it hitting the target straight. Not the target being straight but rather the arrow itself being straight upon impact. If an arrow has any amount of wobble to it you will not only lose energy in flight due to drag but also at impact. This is another reason that paper tuning bare shafts as close to a perfect hole as possible is important. Now there will be a certain amount of oscillation in flight that you can't really control as the arrow flexes due to the force required for acceleration. However if the arrow is properly spined and spin tested that oscillation should stop very shortly after leaving the bow. It will also oscillate again upon impact however if the arrow is flying straight at the moment of impact the force should mostly be exerted in a forward manner. Versus if the arrow impacts off center a good deal of energy will be exerted as the off center portion of the arrow exerts it's energy in the direction of it's travel.

Similar to how it's easy to stick a drill bit straight in a pre drilled hole, however if you tilt the bit to wobble out the sides of the hole it's harder to push in. Of if a car hits a wall dead on square vs an angled glancing blow. If it's angled the rear of the vehicle will snap around. That's because the force of the rear of the car will not be transferred through the car and to the wall, but rather in the direction it was traveling at the time if impact while not centered over the front of the vehicle.
 
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