Kinetic energy

[Eagle1]

Weeeeeelllllllll, don't I have egg on my face, it's been awhile since I did the K E calculation, it is speed x speed x weight div by 450,240.

Speed does over take mass, phyisics,

Sorry guys.
oldtimers dicease

[interceptor]

G' Day Lads,

I posted this earlier on a different thread, I think it adds to the KE debate aswell. You can shoot what you like as hard as you like,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

If the broad head ain't shaving and the arrow not flying true than you WILL lose out on penetration and thus not get the damage down range that you would have wanted. All I am saying is what ever you shoot, if you have over 40# draw wieght and your gear shoots a shaving sharp BH and the arrow has great flight (all this can be done before you even see an animal),,,,,,,,,,,,,,SOOOO the only thing you need to worry about when you see that big buck or whatever is,,,,,,,,,,,,,,,,,,,,,Shot placement.

Geez, glad I got that of my chest

G' Day Lads,

This my first post so be gentle with me

While I have never been to BC, I have hunted some fair bruisers over here in Australia and I have been in on a few hunts with other lads on Buffalo. These are one of (if not the) toughest critters around. Between me and a small group of mates we have tried arrows from 450 grains right up to over 800 grains, all out of current model top line compounds.

IMHO there are two things that make for good penetration.

1, The broad head has to be shaving sharp, not just sharp but SHAVING sharp. If the hairs on your forearm don't run away from blade then it ain't sharp.

2, Arrow flight, if your arrow flies like a dog and wags all the way to the vital zone you will lose heaps of penetration. When you let them go you should see nothing but the nock of your arrow disappearing into the kill zone.



At my first arrow he was quartering away hard and my arrow buried all the way, the broad head stopped on the far side shoulder. My finishing shot went in between the shoulder blades and the BH came out around 4 inches between the front legs (he was laying in the shade feeling the effects of my first arrow) he stood at the shot then dropped for the count after eye ballin me for a few seconds.

I shoot a Mathews Switchback, 73#, 29" draw and my arrows weigh around 470 grains.

Cheers Noel

Cheers Noel

[pupper]

what do ya know, my lighter faster arrow has more kinetic energy...........

I was thinking about this topic over the last couple months and what I had on my heart was this:

we measure our arrow speed coming right out of the shoot, a lighter arrow will be faster at this point but what about at 40 yards? wont a heavier arrow have more momentum and penetrating power at these yardages? a light arrow can be stopped quicker than a heavy arrow right? so this calculation can be a little misleading when we measure the arrow coming right off the rest. So in essence I am wondering, what is the magic combiniation for speed and penetrating power?
for example this video:
http://www.youtube.com/watch?v=uaEWh...eature=related

shows a kid spearing a doe with complete pass through, this is an example of wieght and penetrating power with little speed.

[willyqbc]

everything in archery is a trade-off...there is no free lunch

as pertains to this discussion lets look at a few of the variables

speed is definately an ally if it can be controlled (you can maintain accuracy), however if you go with a very light arrow to acheive a good chrony reading your downrange performace will definately suffer. conversely if you go with too heavy an arrow the range and tragectory will suffer, the trajectory will be a rainbow making yardage estimation absolutely critical, but the short range power and penetration will be better. As a good illustration think of a person throwing a ping pong ball, a baseball and a shot put. the ping pong ball will start out the fastest but will bleed energy VERY quickly and be of little use in a short range. The shot put will have a lot of hitting power but will have a very short range and will drop like a rock as it loses speed. The baseball is the obvious choice.

So for me i like a medium heavy arrow....380-400 grains. I will shoot this arrow as fast as I can while maintaining the accuracy of my groups. From experience, I know this set-up will deliver on any animal I choose to shoot.

Another critical component is being sure you have properly spined arrows....too stiff or too soft will cause a loss of efficiency which will obviously translate into a loss in downrange performance. Coupled with this and in conjunction with your arrow length and fletching choice, pay particular attention to your choice of broadhead weight. Too heavy or too light can also cause inefficient arrow flight and loss of downrange performance.

Just my opinion
Chris

[pupper]

Yah chris, I agree totally with you. So for my settup I am shooting a 361 grain arrow (5575 prohunter) at 27.5" draw. I was thinking of increasing my spine stiffness or switching to FMJ eastons. but I think I am at the right combo right now.

[Kirby]

I'm slinging them with about 73 pounds of kinetic energy.

Haven't had anything debate the power behind it.


An interesting point, couple of years ago I hit a mulie with 70 pounds behind the arrow and it failed to even penetrate to the lungs. Clipped the shoulder, turned and ran down under the hide, I blame the mechs, but it goes to show don't really matter how hard you hit it if your shot placement is off.

Kirby

[Bow Walker]

I stopped using N.A.P. Spitfires for the same reason - not that I hit a deer that way, it's just that on angled shots or bone shots the chances of the mech not opening properly and doing it's job are much higher than with any other head.

I now use one piece broadheads since replaceable blade heads have fairly fragile blades. I like the toughness of the one piece heads.