How to figure KE/ Help pick a arrow

[JimB]

I just remembered,I read an interesting article the other day,by an African archer,on this subject.You might enjoy reading it.It is titled "Momentum VS Kinetic Energy For Dummies,How a Traditional Bow Kills"

He gives his recommendations for momentum needed for different size African game and .40 and up is what he likes for Kudu which are elk sized and up.All your mentioned arrows are that or better.
 http://www.africanarcher.com/momentumKENETICS.html

[ssoden]

Thanks JimB .. very interesting info!!!

[Zbone]

Anyone willing to share a simple momentum formula?

Thanx

[JimB]

I did in my first post above.Multiply fps x grains of arrow weight.Divide that result by 225218.

[Zradix]

if you want really simple #'s to compare just multiply the speed X grains.

Gives the same % difference just don't have to remember 225218...lol

675*160=108000
580*173=100340
500*181=90500

if...
108000=100% (108000/108000)then...
100340=about 93% (100340/108000) and..
90500= about 84% (90500/108000)

What does all this mean...who knows..
One has the most energy, one has the least.
Every one will kill.

If you can shoot it well at all hunting distances I'd go with the heaviest/most energy.

What's fun is to keep adding wt till the wt*fps drops. Then see what you think when you back back down a few grains to the most "energetic" arrow.

Have fun
Good luck on the elk!!!!!    

[R. W. Mackey]

Jim B:  Thanks for adding that link to African Archer, very well written.  I am heading to Africa next year and was wondering about my set up as well.  Seems I will be just fine.
Zradix:  I was thinking of doing just that, adding weight up front until the Slug FPS drops, always fun to play with this.  It seems you can add quite a bit of weight before the number starts to decrease.  Thanks  RW

[JimB]

I don't think the slug fps will drop at all.Momentum increases more than speed decreases.Trajectory will drop and you have to decide what kind of trajectory you need.It is all a balance.