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thoughts on speed vs. Kinetic energy

Lucky13

Lucky13

Member
I saw this posted on another forum and Id really like to get your guys opinions because some of you are some very successful hunters...when purchasing arrows you have to think about a couple of things with speed and kinetic energy being at the top of the list. I purchased a new bow this year and also new arrows...I am shooting Easton FMJ at 10.2gpi...At targets they seem to hit pretty hard but my fear is what would happen at longer distances..40 yrds+...so to you guys that have been successful over the years and those that have killed at longer distances..what do you think? speed or kinetic energy(penetration)
 
Mass and speed= kinetic energy. I like to shoot long distances a lot. I practice at 100 yards all summer and have taken deer at over 80 yards. I shoot as light of arrow as I can so it gets there faster and shoots flatter. Ive figured on them Kinetic energy charts a lot and I'm making up with speed what I lack in arrow weight. I shoot 420 gr arrows out of a 82 lb omen pro and it's puttin around 120-124 lbs of kinetic energy.
 
I also shoot the vap armour piercing arrows which are really small diameter and they alone give me another 5 inches penetration on my target than standard size arrows
 
A heavier arrow will hit harder at longer distances than a light arrow. Light arrows lose their speed faster thus not retaining as much energy or momentum. The only thing you really lose with a heavy arrow is trajectory. My dad shot an elk with easton FMJ and a 125grain muzzy at 40 yards and it completely went through and lodged in the off side shoulder. His bow does not shoot all that fast. I do not believe anything would have gotten through that but it was dead within 40 yards.
 
JasonF said:
Mass and speed= kinetic energy. I like to shoot long distances a lot. I practice at 100 yards all summer and have taken deer at over 80 yards. I shoot as light of arrow as I can so it gets there faster and shoots flatter. Ive figured on them Kinetic energy charts a lot and I'm making up with speed what I lack in arrow weight. I shoot 420 gr arrows out of a 82 lb omen pro and it's puttin around 120-124 lbs of kinetic energy.
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Mass X speed or velocity is actually momentum and not kinetic energy. Two very different things to look at. Your bow is smoking though. Those omens are fast.
 
Momentum is more important than kinetic energy. A slow heavy arrow uses more of your bows available energy it makes your bow more quiet and usually drives arrows into the dirt on the other side of big mature bucks.
If your shooting a normal sized fixed blade head I dont see much of a problem shooting a lighter arrow.
Problems arise when people think they can shoot a huge expandable head on a lightweight arrow with a short draw and 50 pounds, it can work in a perfect world, but the whitetail woods are rarely perfect.
I shoot a 27" fmj and 125 grain heads and the trajectory vs that and an easton lightspeed is within 36" at 150 yards so I cant fathom much trajectory difference inside of normal whitetail ranges 15-30 yards.
Ill stick with my heavy arrows
 
Kinetic energy is useful in ballistics because tissue damage is inflicted by deposition of energy from the bullet. Broadheads, however, need to cut to kill, which is different from depositing energy. Therefore, they need momentum to carry them through the animal (which is the product of the arrow mass and the velocity of the arrow).

To get better penetration, increase your arrow mass (which is easy) and/or increase your arrow speed (more involved). There is a large contingent of traditional bowhunters that swear by extra heavy (200 grains or more) broadheads. I have a friend that pulls a 29 pound longbow and had pass through shots on two whitetails using arrows tipped with 315 grain broadheads.
 
Rich77 said:
Momentum is more important than kinetic energy. A slow heavy arrow uses more of your bows available energy it makes your bow more quiet and usually drives arrows into the dirt on the other side of big mature bucks.
If your shooting a normal sized fixed blade head I dont see much of a problem shooting a lighter arrow.
Problems arise when people think they can shoot a huge expandable head on a lightweight arrow with a short draw and 50 pounds, it can work in a perfect world, but the whitetail woods are rarely perfect.
I shoot a 27" fmj and 125 grain heads and the trajectory vs that and an easton lightspeed is within 36" at 150 yards so I cant fathom much trajectory difference inside of normal whitetail ranges 15-30 yards.
Ill stick with my heavy arrows
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This :)

Inside of 40 you wont see much difference in 50 grain difference but past 40 and you will see it more often. I like to stay around 400 or higher for whitetails and again-past 40 you will miss if you are off 5 yards in estimation whether it be with a 300 fps setup or 275 fps.

Keep your bow quiet-ensure your spine is spot on (most important) and find what is most accurate. I have played the speed game and I find 280 and up you wont gain much. Now I add arrow weight until I get 270-280 and find I can tune fixed blades easier and my arrows hit harder. Its not the perfect shot you have to prepare for but the one that is less than ideal.

Penetration kills.
 
IE the guys worried about arrow speed are more worried about how shiny their truck is instead of what they put in the back of it:)
 
My arrows are 5.2 grains/ in for my bow and are lasers.. Had easy pass throughs on the deer I shot this year. Most importantly it's all about shot placement.
 
I will agree fully with shot placement.
1st thing- quieter bow equals less string jump
2nd thing- a heavy arrow with a razor sharp broadhead will help out 10 fold if something goes wrong and you need more umph behind the arrow.
Long story short, I sent my wife after a doe this year in a stand that I figured she would have shot and been done by 4:00 "she is a lights out shot"
She is shooting an elite hunter, 25.5" draw at 46 pounds.
Carbon express hot pursuit arrows at 332 grains.

I told her to knock a g5 tekken 2 blade "1.5 cut 2 blade expandable" to basically see what kind of penitration she would get with an expandable head.
I got a text 45 mins before dark that she had killed a buck and he was down inside of 40 yards.
I get there and she had hit him nearly perfect but slightly quartered to, she hugged the shoulder and actually burried her arrow in the dirt. Kicker is that it was an 8-9 yr old tank bodied buck more than likely pushing 300 lbs live weight.
It can be done with a light arrow, ive seen it happen under perfect conditions but I always recommend to go heavy on arrow weight.
Speed doesnt kill, a well placed shot with a sharp broadhead that leaves an intrance and exit does everytime though
 
My opinion is that KE is of little importance here in Iowa hunting whitetail - momentum of a heavier arrow could have an argument with environmental situations such as heavy winds rain etc. but truth be told your heavy arrow will never catch my lighter arrow given any ethical hunting situation and when it gets there on a whitetail KE will be far less important than shot placement. Lighter arrow will always get to 150 yds faster and flatter than a heavier arrow even if the lighter arrow sheds speed faster.
 
Archery is a game of trade offs. You almost always have to give up some thing to get something else. In my opinion to much is given up just for speed.
 
HuntNFish said:
My opinion is that KE is of little importance here in Iowa hunting whitetail - momentum of a heavier arrow could have an argument with environmental situations such as heavy winds rain etc. but truth be told your heavy arrow will never catch my lighter arrow given any ethical hunting situation and when it gets there on a whitetail KE will be far less important than shot placement. Lighter arrow will always get to 150 yds faster and flatter than a heavier arrow even if the lighter arrow sheds speed faster.
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KE and the momentum of a heavier arrow would basically be the same thing
 
hoosierhunter said:
I would disagree given plenty of hunters lose deer every year due to lack of penetration. Yes shot placement is a cure all, but this is also real world hunting and things go wrong.
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I agree KE is right behind shot placement. It's like the rage debate, a rage helps make up for bad shot placement and KE does the same thing. Anything we as bow hunters can do to decrease wounding or losing an animal is paramount!
 
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