Light and fast vs heavy and slow

[chopx2]

Originally posted by AdamH:
I know, not pertinent here, but I witnessed my Bud shoot a fat 6 pt. in Md. last year with a "screamin" wheelie bow, 30 yard shot, dead on the shoulder goin in tight behind other comin out, Buck stumbled 32 yards, dead in 3-4 seconds, I took that "pass thru" arrow {soda straw size carbon w/85grn. Thunderhead} home and weighed it on my Digital scale ...... 370 Grains, Total ... Obviously, Speed means something ... I know, Apples to Oranges, but it was Pretty Impressive to say the least ...

I've helped track a couple Fast light comppound rage BH shot deer hit in the shoulder or high in the shoulder/neck area (very close shot)...none found even with a dog, both probably survived and in one case the arrow backed out and there was only about 3 inches of penetration.

My 675gr arrow with a hair popping sharp Grizzly last year blew a hole through the ball and socket of a doe's femur big enough to fit my finger through and still went another 13"through to the other side. I made a bad shot, but she was down in less than 50yds. I'd hate to have that happen with a 330fps 400gr arrow.

Yes straight and sharp are a given no matter what arrow or bow you shoot. Why take a chance?

[Ragnarok Forge]

JDunlap,  Heavier arrows do fly better in the wind.  Especially if you use HFOC and smaller fletchings.

Whittler,  A body in motions tends to stay in motion.  The heavier the body the longer it will stay in motion when it impacts another object.  Physics tells you that the heavier arrow will penetrate better, as does all of the Ashby testing and a whole bunch of dangerous game hunters.  This one is not even in question.  It is firmly proven.

[oxnam]

Here is some research for Dr. Ashby's report that tested a relatively lightweight 655gr arrow which penetrated very well in comparison to the 790 and 900 gr traditional "buffulo arrows".  I believe the lighter arrow was shot from a lighter bow than the heavier arrows.  Distribution of weight seems to be more important that shear mass.

Here is the excerpt from Dr. Ashby's 2008 Part 6 report, but you really should read through it:  "Few bowhunters who've taken Cape or Asian buffalo, me included, would have ever considered any 655 grain arrow capable of consistently providing adequate penetration on massive bodied buffalo bulls. Yet here we are, confronted with one that has done so. On every thorax hit this 655 grain Ultra-EFOC arrow fully traversed the thorax and imbedded deeply in the off-side rib;"

  http://www.tradgang.com/ashby/2008update6.pdf

[tpanic41]

The only way any of this makes a bit of difference is if the heavy arrow is shot at the same speet as the light arrow! If the speed is the same then the weight will trump every time. If the lighter arrow is traveling 10+ fps faster then you will be suprised how comparable the penetration will be.
I shoot 7.5 per #, get perfect flight, and shoot through bear and elk with no problem!

[JimL]

For me I go with heavy arrows which are slower.  The penetration is better but harder on feathers when it goes thru the target.  In my bow the lighter the noisier and the lighter the more hand shock.  It drops more at a set distance but I can't judge distance worth a squat so I shoot instinctive and its not an issue. With compounds I shot heavy, long, and light and was always missing when judging came into play. Now it magically takes care of itself.

[Earl E. Nov...mber]

Can I have heavy and fast?

[oxnam]

Originally posted by Earl E. Nov...mber:
Can I have heavy and fast?

Sure.  Heavy and fast is relative so you should be fine.  Just make sure you only shoot with kids flinging tiny arrows.  Then you will be sure that your arrow is heavy and fast.  

[Javi]

The laws of physics never seem to apply to archery...

[Don Stokes]

Javi, in traditional archery it's the guidelines of physics, not the laws.    

[CG]

Originally posted by Shawn Leonard:
I killed 2 deer and a coyote a few years back.....  Passed thru both deer and entered coyotes left ham and came out up to the fletch in front of off shoulder

That's got to be pretty rare to have 2 deer and a coyote lined up for that shot, huh?    

Seriously, though, I agree with you.

[Bob B.]

The laws of physics never seem to apply to archery...

--------------------

I do not understand.  The laws of physics absolutly apply to archery.  What do you mean?  If you PM me a question, I would be happy to send you a reply that may explain just how physics applies.   A bow is a lever.  An arrow is a cylindar, an 2 blade broad head is basically 2 inclinded plains.  It is easy to caluculate kenetic energy and slug force if the FPS and grain weight is known.  Mechanical advantage can be calculated if the dementions of the broad head are known.  This is physics.  Also we know the gravitational pull of the Earth has a constant due to its mass, generalized as 9.8 meters per second per second.  So the flight of a bullet or an arrow is basicaly the same in seconds before it hits the Earth if fired from the same height, it is just the distancen the projectile traveles as well as its speed that is different.  We can use this to help calculate slug force (momentum).  This absolutely is physics.

Speed matters as does grain weigh.  FPS can be a key element as to arrow "power" thus penetration when combined with certain broad heads, and the meduim they are intended to strike, thus contributing to a leathality factor.  Again, totally physics.  

Bob.

[Ragnarok Forge]

The lighter arrow Ashby arrow discussion point above does not work for 90% of all trad archers.  They are not using EFOC arrows. The light Ashby arrow mentioned is above the bone breaking threshold which puts it into another realm which also does not apply to the light end of this discussion.  The Ashby arrow has multiple advancements that use the laws of physics as they relate to arrow optimization.  The standard light arrow discussed here will not perform like the light Ashby arrow in any situation.

The laws of Physics are just that laws.  We can argue until the cows come home, a heavier arrow for the average archer will still penetrate better no matter the argument made.  I find that those who argue for light arrows have very rarely shot heavy arrows into very many animals.


As before I say shoot what you like and want.  And enjoy the process.  I have no feelings for or against light arrows.  That is a personal choice.

I do say, don't try and claim a light arrow at 10 fps faster will penetrate better than the heavier arrow.  Physics, testing, field hunting experiments, and if you read the full Ashby reports proven testing shows that is not true for any standard arrow as discussed here.  That bird just wont fly!

I have spent enough years using physics in the field of engineering to fully understand the math and if someone would like to post up arrow weights and speeds to match the 10 fps change,  I will be happy to run the impulse momentum equations to resolve the issue.  Again you cannot change the laws of physics.  They always work.

[Bjorn]

Archery is 25% physics and 75% art-I made that up! Making a 600 grain arrow travel faster is physics, and very important.
Making it hit where you want is art; and important too?
Light and fast-heavy and not so fast? Good things to ponder and work on.
At the end of the day it is archery basics that kills-art trumps physics-yay! LOL!

[ishoot4thrills]

You go, Lowell!    

[Javi]

Originally posted by Bob B.:
The laws of physics never seem to apply to archery...

--------------------

I do not understand.  The laws of physics absolutly apply to archery.  What do you mean?  If you PM me a question, I would be happy to send you a reply that may explain just how physics applies.   A bow is a lever.  An arrow is a cylindar, an 2 blade broad head is basically 2 inclinded plains.  It is easy to caluculate kenetic energy and slug force if the FPS and grain weight is known.  Mechanical advantage can be calculated if the dementions of the broad head are known.  This is physics.  Also we know the gravitational pull of the Earth has a constant due to its mass, generalized as 9.8 meters per second per second.  So the flight of a bullet or an arrow is basicaly the same in seconds before it hits the Earth if fired from the same height, it is just the distancen the projectile traveles as well as its speed that is different.  We can use this to help calculate slug force (momentum).  This absolutely is physics.

Speed matters as does grain weigh.  FPS can be a key element as to arrow "power" thus penetration when combined with certain broad heads, and the meduim they are intended to strike, thus contributing to a leathality factor.  Again, totally physics.  

Bob.

Bob, it was sarcasm…. I’m a design engineer  

Don caught it.. .   :D      


Every day on any archery forum regardless of whether it is a traditional archery forum or a compound forum; if hunting is involved there will be many who clearly state and adamantly defend the concept that the laws of physics do not apply to archery equipment.  It’s especially unique to traditional archery where we are dealing with comparatively slow moving projectiles and no matter the analogy, or the science used to explain the physics there will always be those who despite the best efforts continue to sacrifice at the altar of speed at all costs…    

I think I'll quit trying to explain it to them and let them continue happily on their path..    

[AdamH]

I've witnessed this Many times with my Wheelie Buds, NONE of them were shootin RAGE, all were Thunderheads 3 Blade 85-100 grn. heads, All arrows 400 grn. & under {carbon} all from 70# Wheeled Bows @ speeds Well above 265 FPS, Plus ... Again, not for me, but Speed obviously matters, But than, there's no comparison between those Bows and Ours ...

[Jason R. Wesbrock]

A problem that often arises in these discussions is tunnel vision. There are a lot of different factors affecting whether or not a released arrow will result in a clean kill. Arrow weight, at best, is but one of them. If heavier always equaled better, we’d all be hunting with fiberglass fishing arrows weighing over 1,500 grains. Somehow I’d venture to say no one here goes to that extreme. So speed and trajectory are obviously somewhat of a priority.

It has always confused me somewhat the extent that folks will go to debate (discuss, argue, whatever) such minor variations of arrow weight, especially when it comes to hunting whitetail deer. If shooting 700- or 800-grain arrows gives one an increased level of confidence, then on an individual level it makes sense to use those arrows. But several generations of recreational bowhunting history are there for examination, modern attempts to rewrite it notwithstanding. And no, it doesn’t take a 650-grain arrow to kill a whitetail deer, or anything else on this continent for that matter. To me, this heavy versus light arrow debate falls into the category of things that matter more on paper than in the real world.

[Terry Green]

Well said Jason.

And this statement is repeated over and over and don't believe that to be true. "A heavier arrow will always penetrate better".

If you run the momentum numbers on a 50# bow with arrows starting out with 400 grains and go up in weight and running the speed numbers, you will see at some point the next heavier arrow delivers LESS momentum due to decreased speed to the point were the momentum is again LESS. (at least it did with my numbers unless I goofed) So in that case, the lighter of those two will penetrate better.  There is a window of performance with any given bow and arrow weight.  Too light and it decreases....same with too heavy.

Also, you should consider the game you are chasing and how flighty they are.  An 800 grain arrow wont penetrate very good at all if the animal is in Detroit when the arrow gets there.

I personally shoot 580 grain arrows most of the time...sometimes 630 when just shooting hogs.  Speeds of 175-185 @27.5 draw, and I don't have penetration problems on the animals I chase.  Although, I have no problem going lighter when in TX shooting those wired whitetails.   I like to penetrate the earth AFTER passing through the deer.    

[FrankM]

Good point, Terry.

[monterey]

I like heavy and slow.  Just like me!    

Never have thought about it in GPP terms.  Just calculated mine and my 650 grain arrows are 13 GPP in my 50# bow.  Wonder how 8 to 10 GPP would work out in a 35# bow?  (legal for deer and elk where I hunt  :eek:  )  So, at 8 GPP that would be a 280 grain arrow!  Still only 350 grain at 10 GPP.

We like to throw Ashby quotes around, but truly, to understand what Ashby is saying you have to read all he has written on this topic beginning with the Natal (sp) study, right up to his most recent release last December.  It's a lot of reading but well worth it regardless of what conclusions you personally come to in the end.