NH306

Is their anyway to figure out how hard your arrow hits at thirty yards compared to sixty yards. Do you use an equation to figure this out! Any help?

Arthur P

Go to www.bowjackson.com and play around with the ballistics program. Plug in your numbers and it'll give you all kinds of downrange data.

Paul L Mohr

You do realize that nockdown power is myth, both in archery and gun hunting. Neither devolope enough energy to actually nock an animal down, or kill it by sheer shock.

When looking at energy figures keep an eye on momentum as well KE. Both play a role in penatration, as well as many other factors. Like tuning and head choice.

Paul

The Rev

Paul is right.

I think most people get KE and knock down power confused. Or have a vague understanding of it.

bigbulls

Bulletsdo actually generate enough energy to knock down a deer. Problem is that these projectiles expend that energy over time and distance and in all directions and loose mass as they are doing it.

If you were to hit a deer with 3000 foot pounds of KE but that object was a 15 pound bowling ball moving at 120 fps the deer will be knocked right on its arse becasue all of that KE would be transfered to and absorbed by the deer almost instantly and the bowling ball would loose no mass.


But on to the original question. [8D]

Bowjacksons site is a great tool. There are a few things you need to know about your arrow first..... Fletch type and height and length, total arrow weight, arrow outsidediameter, initial speed out of the bow, and arrow length.

Plug all of this into their ballistics calculator and it will give you a good close calculation of what kind of energy and momentum your arrow will have all the way out to 100 yards.

Paul L Mohr

Actually they don't, it has been proven many times. In order to generate enough energy to Knock a 200 lb deer off it's feet at 50 yards the gun would recoil enough to roll you over a few times when you fired it.

They do however create enough of a shock wave to stun the central nervous system of an animal and drop it where it is standing giving the impression it was "knocked down". And that effect isn't even a constant. This usually doesn't actually kill the animal either. Normally they die from loss of blood like any other wounded animal would, they are just stunned enough not to get up until it is too late.

Paul

bigbulls

That's because that energy from a bulletis transfered to the deer over time, distance and direction and it is changing shape andloosing mass as it does it

3000 foot pounds is more than enough energy to knock any deer off its feet provided the object can transfer it to the target in a manner to knock it off its feet.

Paul L Mohr

I miss read your post earlier bigbulls, sorry. I was out cooking some chicken on the grill and it dawned on me you were right. I was going to try and respond before you but didn't get here in time.

I agree with you, it is because of the small frontal area of the bullet. Energy figures on bullets and arrows are VERY deceiving because of this. There is also the momentum issue. I would think a bowling ball would hit much harder as well.

Sorry about that, guess I was reading too quickly.

I like my crow BBQ'd with sweet corn on the side.

Paul

AllenRead

Knock down power is irrelevent to archery. First archery equipment doesn't have enough to do much and second because arrows don't kill with knockdown power, they kill by causing massive bleeding.

Recent research has shown that momentum is the best indicator of penetration and penetration and the resulting bleeding is what kills.