........An simple equation. "would you rather get hit by a pencil going 250 fps or a telephone poll going 150fps ?" Ok to start a new discussion or is it argument....."does speed kill or kinetic energy ?" Personally I would rather take a 243 round than a 50/70. Discussion anyone ? Oops Chris didnt mean to hijack youre thread.
Interesting questions.
First to address your rifle analogy:
You must consider that the 243 is hypersonic and will disrupt much more tissue with hydrostatic shock than a subsonic 50/70 bullet that just disrupts a 50 Cal. surface.
The 243 will dump all of its energy in your body, and probably (Depending on bullet construction) not exit.
Considering the thickness of your body, after punching a 1/2" diameter hole through your body, all of the energy the bullet is still carrying will be useless to cause you any harm.
So, trying to compair light/fast arrows with slower/heavier arrows that are still very far below the hydrostatic threshold, makes the issue of tissue damage caused between bullets and arrows an Apples/Oranges compairson.
Now, Pencil/telephone pole comparison. Would you rather be hit by a little girl on a tricycle peddling as fast as she can, or by an 18 wheeler, going as fast as the little girl can push it?
Again, we have a major difference in mass. To make a fair comparison both projectiles should be assumed being launched by the same bow.
So a 50 Gr (0.007+... pounds) pencil shot at 500 fps (340.9 MPH) would carry about 3.57 Pounds Feet of momentum....
Now take your 1000 pound (7,000,000 gr) telephone pole and drive it a velocity to match the pencil's momentum (Shot out of same bow) = 0.00357 feet per second, (.189+ MPH) . Not much punch.
Also, to be fair, shave down the first several feet on the front of the telephone pole to equal the same surface area as the pencils. Your telephone pole will still only be traveling less than 1/5th mile an hour and very slowly disrupt the same amount of tissue.
The pencil telephone pole analogy reflects too large of a difference in size to easily relate to.
I will concede that a heaver arrow will be better at breaking a shoulder or a hip bone, but will the light faster arrow be sufficient"
I've never had a hunting arrow kill a big game animal by the energy it impacted with. It is the broadhead that causes a bleed out and death, not a stompin impact....
I've broken ribs on both sides of a couple of white tails shot with a 65 pound recurve and 450 Gr arrows. The other broadside hits that didn't strike a bone were clear shoot throughs.
Here is a picture of a deer that a friend of mine shot last year. This is a standard 29" POC shaft. Penetration through the skull was sufficient. (Even wasted some energy by over penetration.)
I guess, I just don't understand why arrows above about 450 grains would be wanted for normal hunting.
Anyway, My 2 Cents
Steve
Certified Firearms & Reloading Instructor.