Kinetic Energy....How much is enough?

[flatlander37]

Just playing around with Stu millers spine chart for a new bow.  Noticed that both the heavy and light setups have almost the identical KE, mostly do to speed differences.  Just wondering if there was a threshhold that trad guys and gals should be over for most big game.  Both setups revealed KE of 36.9 for 9.0 GPP and 37.0 for 11 GPP.  Just thought it would be interesting to see what you guys may have.  Mark

[James Wrenn]

I have shot through deer with eveything from about 17flbs on up but most times I am in the 20 30 range.Does not seem to matter if you take broadside shots with sharp broadheads what the numbers say on thin skinned deer sized animals.

[Jeff Strubberg]

IMHO, KE is a good way to compare bows, but not necessarily a good way to measure the killing potential of a bow and arrow combination.

Having said that, both of those bows are generating plenty of juice for about anything this side of moose.

[Slasher]

I agree with Jeff cuz when you see (theoretical) KE at range figures.. My humble opinion believes just enought to punch through the ribcage and puncture both lungs... Honestly I believe that is under 20lbs...

I would like more and do use a 42# whip with EFOC, a sharp eclipse 2blade, on a well tuned .600 spine AXIS, and have clean pass thru @ 22yds... SO Jeff is correct, you're ready for bear!!! But during the rut I also use a 55# whip with a well tuned arrow just to make sure!!!

[trapperDave]

KE is just a number used to sell compounds  :D

[wingnut]

The numbers in stu's calc do not include the speed of your bow.  Just a theoritcal speed.  Heck I put in a HH for a guy yesterday and it show it shooting over 200 fps.  Never happen unless it's in a indy car when shot.  LOL

So long story short.  Don't believe the KE numbers unless you have your bow speed.  Then throw them out and Calculate momentum.  

Mike

[Richie Nell]

Forget about KE.  Irrelevant.

[flatlander37]

Good reply's guys.  You're very right Mike.  The speed is only theoretical, but fun to play around with in the winter months!

[WESTBROOK]

What Trapper Dave said!

Thats why I chose traditional archery, way fewer numbers to deal with. Dont like to mix math with archery.

Eric

[sou-pawbowhunter]

I'd have to join Wingnut's camp on this one.  Kinetic energy is not a great predictor of penetration, but since it squares velocity, it is a great way to keep selling new compounds.  Momentum is a far better predictor of terminal performance, and up to a point a heavier arrow will always come out on top.

[Jim Wright]

Mark, I.M.O. kinetic energy figures are simply a number arrived at through a mathematical equation. You can get an impressive number with a tennis ball if you get the velocity up, not much potential for hunting though.

[Earl Jeff]

I can tell ya that 32 ftlbs will go through a bear l ike a hot knife through butter.

[legends1]

Earl Jeff,What broadhead did you use on that bear?A 4" wide one i guess.