Arthur P

Good Lord, you guys have been busy! I editted myprevious post, Dave, to respond to a point you made before.

Straightarrow

I wasn't suggesting that is would be some kind of computer capable of taking into account all variables. It would just be used as a guideline for a minimum.

For instance, NY state says to hunt big game, you must use at least at 35 lb bow. Well, as we all know, this may or may not be good enough. For instance, a 23" draw length is not going to do what a 30" draw length will out of that bow. Not by a long shot. We also know that a 250 grain arrow will not penetrate as well as a 600 grain arrow. These are just two variables that are completely left out of the minimum requirement, yet have great affect on the effectiveness of the 35 lb bow. Sure, there are other very important variables like broadhead sharpness, and FOC, but this device could give a good basic guideline on the force needed to at least think about hunting a particular size animal.

Well, the arrow has to go through at least one side of the animal. Ashby's tests had nothing to do with what was required to kill an animal. They have to do with arrow penetration and broadhead toughness. As far as I know, all measured results came from dead animals. Some animals probably had multiple shots put in them to bring them down. The shots that didn't even pass through a rib, probably had nothing to do with the death of the animal, but they were shots he could record if the animal was eventually killed.

_____________

I think you're right about the "come and gone" part. I doubt many would buy it, in this day and age of "speed".

davepjr71

Arthur,

It's not a question of who's right or who's wrong. It's a question of determining what's acceptable. And i agree that you should prepair for the worst. The best thing any of us could do is talk our fellow shooters into shooting more than just the week before the season starts or even not shooting at all until they shoot at an animal.

Straight,

I agree there are way too many variables. 35 lbs is very light in my book. I thought most states used 45 lbs. AndI did agree that when you are shooting equipment that is that light is draw weight the heavier arrow could benefit the hunter. To me you would need some sort of sliding scale. Then you remove using a set weight for everyone.

Of course, I also believe they should make every hunter pass a shooting test before getting their license. And I'm sure I'll get grilled for saying that. i think too many people think shooting a bow is like shooting a gun. just aim at it and you will hit and kill it.

brucelanthier

Maryland - For hunting deer, the vertical bow shall have a full draw and pull of not less than 30 pounds.

http://www.dnr.state.md.us/huntersguide/weapon.asp

Arthur P

Agreed, wholeheartedly. Unfortunately, that's something the entire archery world has been wildly unsuccessful at getting done.

But are the manufacturers pitching in and helping to improve the situation? Hell NO.To the contrary, nearly every bit of advertising copy for new bows, arrows, mechanical broadheads, etc focuses on how much EASIER it is to shoot well with their products. Which most people seem to correlate with how much LESS they have to shoot and practice.

I've never understood it, but there is a gargantuan number of people calling themselves 'bowhunters' who seem to think shooting a bow is a chore to be avoided.And those seem to be the very people that the marketing specialists are targeting. [>:]

Minimum arrow weight is a poor solution, admittedly, but what else is there? The human critter is a lazy slug. He won't do anything he doesn't want to dounless he absolutely has to. Keep that in mind.

We can't FORCE people to practice. We can't FORCE them to enjoy archery. We can't FORCE them to take educational classes in archery physics and mechanics and, even if they did,we couldn't FORCE them to understand a word of it.

I feel minimum arrow weight is the one thing we CAN mandate, under force of law, that has the best chance of making postive changes in the wound/loss ratio and fending off the anti's. Some guys might have to sacrifice and shoot arrows that weigh 50-60 grains more than they really like. They might have to endure a 15-20 fps loss in speed and not be able to brag their hunting rig shoots over 300 fps. They might have to endure an increase in penetration potential with very little impact on their trajectories over typical hunting distances.

I'm sorry for all that. I'm sorry that we have to have game laws just because you can't count on people to always do the right and ethical thing without someone looking over their shoulder. I'm sorry that so manypeople can't learn to love archery the way we do. I'm sorry so many can't even grasp the fundamentals of physics as it pertains to archery. I'm sorry so many head to the woods every year without knowing the anatomy of their intended quarry, so they'd know where to place an arrow. I'm sorry that so many think shooting well enough to hit a paper plate at X number of yards makes them 'hunt ready.' I'm sorry so many guys won't be able to WOW the bystanders with their arrow speed at the archery range with 400 gn arrows.

I'm even sorry I can't say the minimum arrow weight should be 450 grains.

BobCo19-65

I'd just add two words to that quote:

bow_hunter44

Arthur, I couldn't agree more. It is absolutely true that forcing a person to practice, among lots of other things is impossible. Althoug, why forcing someone to practice is a mystery to me. There is some sort of viceral satisfaction in hurling a projectile at a target, and having the projectile hit the target. It doesn't really matter what the projectile is either. Modern compound bows are a joy to shoot, you being a tradtional archer have known thejoy of no hand shock, super quiet shooting for years. Besides, we owe it to our quarry to practice. They are magnificant, respect worthy, practice worthy animals!

Here is a quote from Dr. Ashby's work (fascinating reading) about momentum and KE and how it applies to arrows with the same KE but different mass.

"Given two arrows of equal momentum, but with one deriving a greater portion of its momentum from mass than the other, the heavier arrow will change velocity (decelerate) at a slower rate as it passes through the tissues. In other words, the heavier arrow will retain a higher percentage of its impact velocity at any given time period during its passage through the animal’s tissues, thus it also retains a higher momentum at any given point during the time required for the arrow to penetrate."

bow_hunter44

Even more great stuff...

"
ALL MOMENTUM IS NOT THE SAME

Given two arrows, identical in shaft and broadhead materials and profile, and having EQUAL momentum, but possessing UNEQUAL mass, the arrow deriving the greater portion of its momentum from its mass will penetrate better. The Laws of Physics requires this to be true, andALL of my field test data validates this to be the case.

To say this in another way, arrow momentum derived through increasing arrow mass results in a greater gain in penetration than does momentum gained by increasing an arrow’s velocity. This is true because the tissue’s resistance is increased by the square of the velocity."

The reference I have been quoting is great stuff. I can't wait to study Newton's Laws with my physics class. I can incorporate two topics that I dearly love!

BTW - here is the URL to the reference...

http://www.tradgang.com/ashby/Momentum%20Kinetic%20Energy%20and%20Arrow%20Penetr ation.htm

davepjr71

I find shooting a pleasure and never see it as something I have to do. i stopped for a while because my last bow stunk and whenI pulled out my 17 yr old bow I enjoyed shooting that more.

For the record. I've never bragged about speed and that isn't why I bought the bow I have or shoot the arrow I have. If that was the case I would shoot 85 or 100 gr tips instead of at least 125's.

One comment on why we won't see pendulums at the pro shop. It isn't because today is all about "speed". Twenty years ago I didn't see them in the shops either. It's because most people are not interested in the physics behind anything in life. It's sad in my opinion.

Bow,
Not to burst your bubble.

You are like 17 pages behind. We've gone over this already and have moved on to bigger and better things.


Yes, the square if all things are equal. But an arrow with a smaller surface area will have less resistance and therefore the effects of friction are not as great as the square of velocity. This is the problem that I encounted going from college classes to the real world in my profession. In college all tests are done trying to use equals to relate 2 items. however, most of the time in real life that is not hte case. Some guys stick with "Well, this is whatI learned in college." and have a hard time figuring out real world electrical power problems.

Yes, the basic laws of physics hold true. However, never forget the variables. Maybe try to relate that to your students as well.

bow_hunter44

Actually I am not like 17 pages behind. I am like, current. I have read them all. Additionally, I am aware that there are many variables that contribute to the penetration of an arrow (material of construction, diameter, coefficient of friction, etc., etc.). I am also aware that changing more than one variable at a time muddies the water of drawing any meaningful conclusions about the outcome of an experiment. What I wasn't aware of was that this was not a public forum in which I could impart any information I felt the major urge to impart, regardless of the "bigger and better things" one perceives to be the topic of conversation. Forgive my trespass. In the future I shall endeavor to be more mindful of protocol. Perhaps seeking your permission prior to submitting a post would be appropriate?