I would've thought the complete opposite. What your daying Brett Is that If your broad head ferrel Is bigger then the arrow diameter It's causing more friction? I could understand If the arrow was bigger then the broad head. Did I miss Interpret this? lol!
I think so. He says "if it (broadhead ferrule) is not a seamless fit (same size as the arrow) or at least a little bigger, penetration will be decreased"
Think about this...if the ferrule is smaller than the diameter of the arrow, the broadhead will penetrate and then the friction will catch on that little lip of the arrow that is not covered by the ferrule. Now if the ferrule is a seamless fit or slightly larger, the broadhead will penetrate and their will not a be a lip, therefore the arrow will continue to penetrate without as much resistance.
No, I am saying if the broadhead ferrule is SMALLER than your arrow diameter it causes more friction.
I agree with this Brett. I think you said the complete opposite In your 1st post that I quoted below. Lets look at this another way though. If your blades are cutting, their leaving a much bigger path then the size of the ferrel no matter If there's a lip or not.
Careful here. We are talking about friction due to aerodynamic drag. Google "drag force". Area is part of the equation. The drag coefficient will also change ( for the shaft) depending on the size of hole being cut, the diameter of the shaft and probably lots of other stuff too. Either way we agree on the true issue.
Glad we can agree I wouldn't think aerodynamic drag would be a factor at and beyond the impact point on the animal. At that point I would think the surface pressure / friction relationship would have more of an effect on penetration. Granted, before the arrow gets there, aerodynamic drag definitely has an effect on the amount of energy the arrow has at the target. I was touching on penetration/friction in-target relating mostly to these statements (which are correct, just for the wrong reason - it's not surface area that governs friction in the target but rather pressure on the surfaces):
Good point. I would think it is a combination of hydrodynamic drag and also the normal force and friction coefficient. The drag force was what I could gather from the phd article that was referenced. I don't know enough to know if that simplifying assumption is an accurate approach... or maybe I misinterpreted his analysis. It was a little indirect and wordy for me!
If I could point to something I brought up but perhaps did not fully flesh out: The retained velocities of more massive (i.e. heavier) projectiles are always higher at extended ranges. In archery, this is particularly evident at ranges of 60 yards and greater. If we but watch one Saturday’s worth of archery hinting shows, we will see repeated instances of “professionals” using state-of-the-art equipment, shooting beyond ethical distances because they have been lulled into believing their super fast rigs will atone for all sins. You can always spot these situations. The arrow starts out as a blur on camera and then about half way to the target it rapidly arcs downward while loosing half of its initial speed. Then, upon striking the animal, the arrow only penetrates a third (or less) of its length the way into the poor beast. Then the intrepid professional cuts to the next morning. He makes profuse protestations of being unable to sleep the night through because he had decided to “back off” and wait for morning instead of “pushing” the deer. In English this means: My equipment combination at that range was ineffective or the shot was misplaced or both. Assuming the shot was accurately placed, had the arrow adequate inertia/momentum and retained velocity, even at the longer distance the initially slower arrow would have produced much better penetration because it would not have shed as great a percentage of its velocity during the time of flight. In the world of long distance firearms shooting, the folks who consistently take home the records, the trophies or the bad guys all use heavy weight projectiles for this exact reason…retained velocities and flatter trajectories. Yes, a heavier projectile will trace a functionally flatter arc over an extended flight and when it arrives, it will have retained a higher percentage of its original velocity thereby increasing the weapons “effective range”. By the way, I shoot a 495 grain arrow at 235 feet-per-second. My regular practice range is 55 yards and those puppies hit hard. If I could only find a nice deer stupid enough to stand still long enough…
being my knowledge of bows and bowhunting could fill a teacup and leave room for cream, i can relate to the firearms side of this. think of it this way, compare a 9mm to a .45 auto round. The 9 moves alot faster, and has a greater effective range over the .45, but on target, the .45 does a hell of alot more damage. i would think this would translate to arrows as well.... just my thought on this, and why i carry a G21SF over a G17, who needs round count when you have stopping power!
Two arrows of the size, different weights encounter the same windage. The heavier arrow will indeed travel longer at grate distances. However, I think the difference in flight at 50 yards is more a product of the angle of the shot than it is due to the lighter arrow losing engergy to friction. In other words, gravity is the main factor in play here. Consider the angle you would have to hold a 200 fps arrow vs. a 300 fps arrow. Put another way, provided a light, but safe to shoot and a heavier arrow are held at the same flat angle, the faster arrow travel further before hitting deck.
You are right but what is your point? Speed is very over rated ( as most have said here), but I dont feel that an extremely heavy arrow shot at a much slower speed is the answer either. IMO the game being hunted should dictate what set up you use so heavier arrows for larger game. I use a 370 grain Easton Axis arrow with a grim reaper broadhead for my white tale hunting and I get GREAT penetration. 370 grains is not a super heavy arrow nor is it a super light arrow. It is about 5 grains perpound which is recommended by most manufacturers. Another thing that really has not been brought up is spine. In order to go super light in most cases one has to drop to a weaker spine, which would make accuracy at 30+ yards and with windy conditions much more difficult.
Gravity affects all bodies equally (Leaning Tower of Pizza and all that). Both of the arrows in your example will hit the ground at the same time in seconds. The faster arrow will have traveled farther in the same amount of time. After forty yards, the retained velocity of the heavier shaft begins to overcome the initial advantage of the faster/lighter arrow. In essence, sights are designed to compensate more for the effects of gravity during time of flight than air resistance created by drag.
Konrad, I just wanted to clarify the factors in your post which may have led some to believe that the lighter arrow was bleeding energy very quickly, and point out that gravity is the main player in arrow trajectory. Anyway, it sounds like we are in agreement. Perhaps the largest culprit in the aforementioned lack of penetration (other than the obvious poor shot placement) can be attributed to the larger cutting surface of expandable blades. Grim Reaper makes a 1-3/8” and 2” models. Interestingly enough, the 2” model is called the White Tail Special. I prefer the 1-3/8” model, as there are no free lunches in engineering and cutting surface comes at the expense of penetration. Regarding your set up: when you talk about arrow weight, do you mean bare shaft? I just checked my arrows using the CX Maxima chart; I'm shooting 5.1 grains per pound with a 28" arrow set at 26" draw length set at 72 pounds. However that is the total arrow weight (except blazer vanes) with standard nocks, insert, collar and 100 grain tip.
I have shot deer with both fast light shafts (GT velocity pro 300) and heavy slower shafts (easton FMJ 300), both gave me pass through shots at distances of 43 and 48 yards, why? because of the razor sharp tip on the front of them! I bet if i shot those deer with a field point niether would have passed through. fast vs. slow, will only go as far as the head you put on it! I think you guys argue about this stuff more than politics! lol but its always interesting reading!
Pastor, My “standard” completed arrow consists of a 29 inch, 2413 XX-78 Eclipse with insert, Easton Super Nock, Super Uni-bushing, three, two inch Blazers and a 100 grain 2 blade Magnus Stinger broadhead for a completed arrow weight of 495 grains. My ’07 Bear Truth (318 fps IBO) is set at 62 pounds draw weight and 27 inch draw. The chronograph at the Sportsman’s Warehouse showed a very consistent 232 to 235 fps. By the way, I think you are right about the never-ending fast/light-slower/heavy discussion. The impetus for writing my initial post was for rebuttal to the erroneous conclusion that e-mail news letter was arriving at. The uninitiated are easily led to conclusions not necessarily based in fact or real world experience. Most everyone who responded had strong opinions based on their own experience. My post was really aimed at those just beginning to get their feet wet in the sport. At the beginning of my sporting career I studied everything I could find on the subject of African hunting. At the beginning of the modern firearm age and the advent of smokeless powders the light/fast crew was convinced they had finally discovered the end all be all for dangerous game in the .284 class weapons. While Pondoro Taylor was eminently successful in killing the greatest number of elephants any hunter has ever recorded using a 7mm bolt action, he only took perfectly aligned brain shots. Other hunters seeing his successes attempted the same feats without the required physical ability, practice or real world knowledge…and died horrible deaths for their efforts. Not to mention the inflicting of untold suffering on the animals. I realize our discussion is related to the deer family of critters; however, I am convinced those same principals of ballistics in firearms technologies apply directly to those of archery. I must admit I do enjoy the discussion Thanks for your input, K
This one deserves more attention than it gets. I too shoot an Easton XX78 2413, same nock but a different broadhead, Wasp SST Hammer, 85 gr. Also, I shoot three 4" feathers and my arrow weighs about 450 gr. I draw 66 lbs with a 30" draw length. Bow shoots this @ 275 fps. Producing about 75 ft/lbs of KE. I used to shoot a 2213 set up the same but weighed about 425 gr. I also shot it at 275 fps, producing about 71 ft/lbs of KE. Only 4 ft/lbs difference but the stiffer arrow (2413) penetrates much better being the stiffer arrow.
Recalculated and came out with 13.296 grains per inch for a fully dressed arrow. Total weight at 28" is: 372.29.
