Good Read: Speed vs Kinetic Energy

[hully1029]

http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_5.htm

http://www.huntersfriend.com/carbon_arrows/hunting_arrows_spine_chart_by_deflection.htm

http://www.huntersfriend.com/carbon_arrows/hunting_arrows_main_custom_all_specifications.htm

i dont know if these links have been posted before, but they answered alot of questions i had and help me make my decision.

[hully1029]

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[Mudslinger]

KE, is not "knock down power" when it comes to bowhunting. That is very misleading. Bowhunting involves a sharp BH and proper shot placement along with a very important aspect that most do not recognize or understand or figure and that is "Momentum", the ability of the arrow to penetrate. Penetration is what we are all after aren't we? The vast majority of the time, Momentum will go up no matter if the speed drops and the KE remains virtually the same. I have more KE and way more momentum with an arrow that is 150 grains heavier and 44 fps slower than the arrow I use to shoot plus a very quiet bow at the. This combo is also very forgiving and more accurate for me. Good read though and informative.

[JW]

KE, is not "knock down power" when it comes to bowhunting. That is very misleading. Bowhunting involves a sharp BH and proper shot placement along with a very important aspect that most do not recognize or understand or figure and that is "Momentum", the ability of the arrow to penetrate. Penetration is what we are all after aren't we? The vast majority of the time, Momentum will go up no matter if the speed drops and the KE remains virtually the same. I have more KE and way more momentum with an arrow that is 150 grains heavier and 44 fps slower than the arrow I use to shoot plus a very quiet bow at the. This combo is also very forgiving and more accurate for me. Good read though and informative.

In short. KE is a buncha crap!!!

Mornin Slinger!!!!!

[Mudslinger]

Mornin'! Thought I might stir the pot a little this morning!

[Aspect Outdoors]

Interesting read.

Modern equipment has limited the impact of this discussion. I shoot 70# pounds with a 29" draw. My last arrows were 420 grains travelling 290 fps. The penetration was unreal. In fact the only thing that I did not get full pass through on was a double shoulder shot on a 200# hog. Even that had buried up to the vanes.

Switched to a lighter 351 grain set up this year. I have no doubt at about 74 KE it will be fine for anything I'll be tackling.

Edit: broadhead selection to me has always been more important. I can shoot a 600 grain arrow 400fps and not penetrate if your flinging rubber blunts

[Mudslinger]

I don't know, a 600 grain arrow flying at 400fps just might blow a rubber blunt threw something! sure would like to have a bow that would do that!

[nock1]

This is an ongoing debate for years and will probably stay that for ever. But the physics of it is, a heavier arrow will keep kenetic energy farther down range (30-40+ yards) than a lighter arrow. The latter will obviously fly faster, but won't maintain its speed farther out. So... The heavier arrow will penetrate better at longer distances but a lighter arrow will penetrate better (lighter to a point) at higher speeds, closets to your target

[JW]

This is an ongoing debate for years and will probably stay that for ever. But the physics of it is, a heavier arrow will keep kenetic energy farther down range (30-40+ yards) than a lighter arrow. The latter will obviously fly faster, but won't maintain its speed farther out. So... The heavier arrow will penetrate better at longer distances but a lighter arrow will penetrate better (lighter to a point) at higher speeds, closets to your target

A heavier arrow penetrates better at any range. Thats not based on theory. Its from expirence on 250+ pounds hogs. A 600 grain arrow with the same head will pentrate better at 10 yards than 375 grain arrow on a big boar 90% of the time. ke in a nutshell is potential. Momentum is more like actual for a lack of better terms.

[icetrauma]

A heavier arrow penetrates better at any range. Thats not based on theory. Its from expirence on 250+ pounds hogs. A 600 grain arrow with the same head will pentrate better at 10 yards than 375 grain arrow on a big boar 90% of the time. ke in a nutshell is potential. Momentum is more like actual for a lack of better terms.

So what you are trying to say is it's easier to stop a VW Bug going down hill, than stopping a Ford F250 Super Duty going down the same hill.

[JW]

So what you are trying to say is it's easier to stop a VW Bug going down hill, than stopping a Ford F250 Super Duty going down the same hill.

I dont recall saying anything about shooting vehicles. P

Broadhead design has alot to do with it as well. On tough hard to penetraete animal bottom line is not all heads penetrate the same. If a person thinks they do they simply have not shot enough big critters. Mature boars seperate the penetrators from the non penetrators in a heart beat. Im not talking about exceptions here and there. Im talkin on a consistan basis.

[icetrauma]

i dont recall saying anything about shooting vehicles. p

lol!!!!

[ItsLeo]

It's really pretty simple.

Momentum is what determines how much Force it takes to stop the arrow.

Kinetic Energy is it's potential for how much distance the arrow will travel (penetrate) when it encounters that Force.

Think of Momentum like it's the size of the engine in a truck. And Kinetic Energy is how much gas it holds.

Ragin' is correct the heavier arrow will out penetrate the lighter one at any range out of the same bow with one glaring exception that is extremely common.

What an awful lot of folks do when they are "investigating" "heavier" arrows is simply screw a heavier head on their existing arrow with no regard for what that does to the spine of the arrow. Then they shoot the both the lighter and heavier head into a target. When the "heavier" arrow fails to out penetrate the lighter arrow they think they have proved the "heavier" arrow has no advantage. This is not a good test! You will loose Kinetic Energy and not get as much Momentum as you should with an underspined arrow! You will also loose penetration with an underspined arrow because it will flex too much and loose Momentum rapidly before it penetrates. All you prove when a lighter head out penetrates a heavier one is that your shafts are underspined for the heavier head!

[JW]

It's really pretty simple.

Momentum is what determines how much Force it takes to stop the arrow.

Kinetic Energy is it's potential for how much distance the arrow will travel (penetrate) when it encounters that Force.

Think of Momentum like it's the size of the engine in a truck. And Kinetic Energy is how much gas it holds.

Ragin' is correct the heavier arrow will out penetrate the lighter one at any range out of the same bow with one glaring exception that is extremely common.

What an awful lot of folks do when they are "investigating" "heavier" arrows is simply screw a heavier head on their existing arrow with no regard for what that does to the spine of the arrow. Then they shoot the both the lighter and heavier head into a target. When the "heavier" arrow fails to out penetrate the lighter arrow they think they have proved the "heavier" arrow has no advantage. This is not a good test! You will loose Kinetic Energy and not get as much Momentum as you should with an underspined arrow! You will also loose penetration with an underspined arrow because it will flex too much and loose Momentum rapidly before it penetrates. All you prove when a lighter head out penetrates a heavier one is that your shafts are underspined for the heavier head!

X2. Ya gotta be spined right. As far as penetration, good head design and another thing that is over looked it a straight flying arrow. And fyi, casio's dint kill nada!

[Mudslinger]

I don't know about that Ragin'. You throw a Casio just right and it hits just right, it could kill someone!.

Have a good trip with Gen and the kiddos yesterday?