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RE: Speed is all you need! (?)
 

I am not sure what you mean by that???

If you would like me to derive some equations I would be more than happy to.(I have a pretty good math background.) Let me know what would be helpful.

RE: Speed is all you need! (?)
 

We' ve already got ' em, don' t we, Frank? I was getting 250 fps with 580 grain 2315' s from my old Hoyt Raider at 70 pounds with the old style Command Cams, Intruder limbs and 32" draw, using an extra long string loop. Got about the same speed with an old Darton Lightning. Hand me a brand new hotrod BowTech and I bet I could beat the devil out of that speed....

RE: Speed is all you need! (?)
 

This is recopied from page three of this thread . . . and it derives the 4502400 and presents the logic to do so . . . it was originally derived by Lrac.

Talked with Dick_cress and we thought this info may be of some use to a few of you out there.

mass 6. Abbr. m Physics. The measure of the quantity of matter that a body or an object contains. The mass of the body is not dependent on gravity and therefore is different from but proportional to its weight.
---------------------------------------------------------
Excerpted from American Heritage Dictionary
Copyright © 1997 The Learning Company, Inc.

The above definition captures the gist of the problem. The equation for kinetic energy is correct: K.E. = ½ mV2. What is missing is the conversion factor for changing " weight" to " mass" . To do that you must divide the weight of the projectile by " g" , the value of the acceleration of gravity : 32.16 feet per second (or 32.174 fps depending on your reference). Also, to arrive at an answer in foot pounds you need to convert " grains" to " pounds" . There are 7000 grains in a pound, so you also need to divide the weight (or mass) of the projectile by 7000.
K.E. = kinetic energy (in foot pounds)
g = acceleration of gravity = 32.16
w = weight of the projectile (in grains)
m = mass of the projectile
V = velocity of the projectile (in feet per second)

K.E. = ½ m V²

or

K.E. = wV²/ 2g x 7000

or

K.E. = wV²/450240


For some strange reason I can' t seem to get the underline or division line to work. The above formula is wV² divided by 2 g x 7000 or wV² divided by 450240. Hope this helps.

RE: Speed is all you need! (?)
 

I guess my only stink with that Pa, is I would wouldnt be suprised at all to say almost or slightly over 70% of the speed bow folks to be using range finders. That figure could and probably is quite higher.

That said, if the only loss is pre determining distances and or marking them out prior to a hunt in some way shape or form for a slower heavier, higher momentum arrow and even some arc to it, heck for that matter, what you all would consider low KE 30-40foot poounds, And achieve almost total penetration on something oh, say the size of a average bull moose

VS

The guy shooting screaming super light arrows arrows for the sake of his/her lack of ability of judging yardage in which case he more likely owns and uses a range finder to help him/her aid in pin point accuracy, shoot and wound a moose in only hitting a rib bone.

(Woody, you can go ahead an pipe in here on knuckleheads moose experience before he left)

Now does it really matter, you aint hunting moose.....probably not. But it does when a situation like Krisken states, in shooting a shoulder and getting no penetration. I think I preached that gig back from post one......a worst case scenario.

The problem with the two equations is one factors in both speed and weight un biasedly. The other is speed biased.

One is also measured only till impact where the other is what is going to help carry the object of concern through, be it a bullet, arrow, slugs. (the only difference is in how they kill).

There is also some good reading on Bob Robb' s elk hunting book. Col. Ret Bodington has a great article in there. You would be amazed to see some of the same things when it relates to the thought process and reasonings to penetration from rifles to bows. Just something else to get a good foundation of knowledge from even if its from the dark side .....[&:]

Alaska is one of the few states I know of (actually the only but I know if I say only I' ll be wrong), to have an arrow weight standard.

There is a slight flaw to even this. Espically when they are trying to madate a 900 grain arrow for critters like moose and bison, and a 750 grain arrow for caribou and blacktails sized critters. Its a point of dimishing returns. I dont think many folks push the to heavy issue to much as they really feel to heavy isnt an issue. I however feel differently. I also feel this is where I agree with Pa a slight bit albeit for different reasons.

I also was helping out the state in its bowhunter ed classes. I think what bothered me the didnt have anything to do with light speed folks. It was the amount of archers and " bowhunters" out there that just couldnt hit the broad side of a barn from the inside out! 5 of 8 arrows in the kill zone, with 2 arrows in the high 20 yards, everything else 22 yards or less on deer sized animals, and they manage to fail time and time again, thats with the use of range finders, sights, optics, let offs, release, gizmo this gadget that. It has nothing to do with them not handling speed up here, they cant figure out what end is up! :(

RE: Speed is all you need! (?)
 

Which Knucklehead Dan? There are so many. [:' (]

RE: Speed is all you need! (?)
 

Where to begin? Ahhh, my eyes are killing me as I just spent the last half hour typing up a post for a thread regarding single/dual cams and split/solid limbs over an Edersbow. My fingers are tired and my mind is about fried but here it goes....

Arthur,

Yes, you and I come close to that measurement but it takes a long draw length and a relatively heavy draw weight to achieve it. I am referring to the time when the average archery can get away with those speeds at an average draw length and a medium draw weight (60 lbs). Ofcourse, I have a feeling I know what your answer is going to be...." ..then I would switch to an 800 grain arrow for even more momentum while still sticking to my 220-250 fps speed range..." ...or at least that is how I would approach it from your standpoint. :)

Lilhunter,

Yes, I would bet you are correct. I use a laser rangefinder and my bow speed is usually in the mid 270' s range with a 430 grain arrow. I would not call that smokin' fast but a little better than what I have seen from the average bowhunter' s setup. My view of this situation and in defense of my setup is " better safe than sorry" . Assuming " left to right" accuracy is a given then only vertical accuracy needs to be considered. Using a laser rangefinder and a relatively fast setup greatly reduces the chance of a vertical miss or wounding shot.

Now, given the two scenarios you illustrated I believe the former to be the most efficient and potentially the most ethical since it results in either a miss or a complete pass through. However, given unlimited options I would choose neither and that is a direct result of my continuing perspective of moderation. I do not want a 330 fps arrow that only weighs 330 grains and has plenty of KE and relatively low momentum....but on the other hand I do not want a 200 fps arrow that weighs 650 grains and has relatively good KE and plenty of momentum but also has an arching trajectory.

I want the best of both worlds and regularly suggest something in between both extremes. Shoot a 260 or 270 fps bow with a 425-450 grain arrow that will not only have plenty of KE and momentum but also a relatively flat enough trajectory to help with errors in judging distance.

Ok, I think it is time for me to call it quits for the night....my eyes are starting to loose focus....:)

RE: Speed is all you need! (?)
 

I shoot a bow with 241 fps and a KE of 60 ft-lbs . . . and I carry and use when I can a laser rangefinder. [X(]

Washington State does have legal requirements for our arrows. Expandable are prohibited. We must shoot an arrow of 20 or more inches in length (including broadhead) and it must weigh 6 gr per pound of draw weight.

Kinetic Energy is a law of physics but not an instrument used to measure penetration. It is a product of and is dependent upon mass and speed. It is logical . . . to me at least that the greater the KE the more penetration we can expect. Each of us must develop, with our equipment the combination of two that works for us and develops a KE factor that will allow us to harvest the game we are after.

So far all of my shots are passthroughs so my combo works great for me.

RE: Speed is all you need! (?)
 

well said Pa!

Dick, you contradicted yourself. No worries, I see where you are are going.


Woody,

I cant remember his name, drove the lil purple car, shot for John (I believe), and it wasnt Butch. Army guy, had a daughter...sure that helps lol.

RE: Speed is all you need! (?)
 

Frank, maybe someday they' ll get to the point where Joe Average can shoot a 600 grain arrow from a 60 pound bow at 29" draw. I just hope they can figure out a way to do it and still keep bows shootable for newcomers and the couch potato bowhunter wannabes that Lilhunter spoke of.

I' ve overseen several proficiency tests that our club conducts for a nearby WMA and I' ve seen exactly the same thing he has. Guys coming in, registering and wiping cobwebs off their rest as they walk down to the course. The rules call for 14 deer sized 3D targets, 30 yards max, 10-8-5 scoring and 80% of the maximum possible score to qualify. Basically an 8-ring on each target. Binoculars and rangefinders are allowed. Slam dunk for someone who regularly shoots 3D, no matter what weight arrows they shoot or what speed they' re getting, even without a rangefinder. You' d be amazed at how many people carrying state of the art bows and carbon arrows can' t break 100 points on the round.

A miss is a miss, no matter how fast the arrow is flying.

But that' s not really the point. If bows get to the point where only experienced and skilled shooters can be proficient with them, then it' s going to be awful tough for newcomers to get into the sport. As those experience and skilled shooters grow old and drop out, where are the newbies going to come from to replace them? You reckon they' ll have to start out with traditional to learn how to shoot and then work their way up to compouds? Or will they just blow it off altogether? I' m thinking that when your scenario comes to pass, it will be the beginning of the end for hunting with compounds and traditional will reign supreme again.