Your right sounds like a shot placement issue...
KE and the momentum of a heavier arrow would basically be the same thing
Nope you would be wrong... Momentum is what delivers the KE. Double the speed and you double the Momentum of the arrow, but double the speed you quadruple the KE, so I don't understand a lot of the comments on trading speed for KE - in Iowa it don't matter on whitetails... KE Example (What Kills) 350 grain arrow at 320 FPS = ft.lbs KE 430 grain arrow at 280 FPS = ft.lbs KE Momentum Example (What Carries) 350 grain arrow at 320 FPS = slug ft / sec 430 grain arrow at 280 FPS = slug ft / sec So in Iowa speed is what delivers out to 40-50 yds. on whitetails. Now with that being said if you shoot through brush, trees, concrete, or have a shot at an Elk at 70 yds (not likely in Iowa) a heavier arrow would work better. Heavier arrow cost speed which cost KE you want more KE and less guessing distance go lighter. By the time my lighter arrow slows enough to match the KE of your heavier arrow they will be out of sight. Huge misconception that need to be corrected, when bows were slower heavier might have carried more KE, but time have changed...
Yes increased speed offsets the weigh carried, but to a distance because the lighter arrow is shedding speed quicker and in Iowa that distance is outside ethical whitetail range. Would have to know the set-up to make second assumption check the charts. lighter arrow does not necessary lose more energy on impact more KE the more likely the deeper penetration. So... Shooting same bow 340 IBO into foam deer target. lighter arrow will have more penetration at the shorter distances than the heavier arrow. From my experience if you shoot same bow - at 5 Grain / LB draw you will see better penetration than a 7-8 grains / LB arrow out to distances conducive to whitetail hunting in Iowa. 3D shooter should be able to contest and the preceding is the science behind it.
My arrows are 5.2 grains/ in for my bow and are lasers.. Had easy pass throughs on the deer I shot this year. Most importantly it's all about shot placement.
Bows have changed but all of them still do a better job of getting the energy into a heavy arrow. Same bow shooting two different weight arrows... the heavier arrow will ALWAYS have more KE in it, even though the lighter arrow will ALWAYS have more speed leaving the bow. I do not think it is a significant concern for most of us but some of you are misinformed on how a bow works.
It is sort of like getting closer to a dry fire. The lighter the arrow, the closer you are to a dry fire. The energy is still in the bow, rather than in the arrow. That is also why a heavier arrow will quiet down the bow (because they absorb more of the energy).
Bows have changed but all of them still do a better job of getting the energy into a heavy arrow. Same bow shooting two different weight arrows... the heavier arrow will ALWAYS have more KE in it, even though the lighter arrow will ALWAYS have more speed leaving the bow. I do not think it is a significant concern for most of us but some of you are misinformed on how a bow works.
It is sort of like getting closer to a dry fire. The lighter the arrow, the closer you are to a dry fire. The energy is still in the bow, rather than in the arrow. That is also why a heavier arrow will quiet down the bow (because they absorb more of the energy).
No seems you may have been misinformed once the arrow leaves the bow its all about weight and speed - see the link to the chart I think it will give everyone a great resource for better understanding all of this. You want KE you will go with speed. Your above comment is true ONLY if the speed does not change and we all know a heavier arrow will be slower out of the bow.
http://archeryreport.com/2009/12/arr...ference-chart/
I do agree that when the arrow leaves the bow it is about speed AND weight. I also said that the lighter arrow is faster, which is the same as your comment that the heavier arrow is slower. When talking KE or momentum, your heavier arrow wins after it leaves the bow. This is for hunters shooting broadhead tipped arrows into live animals. Shooting into foam is apples and oranges when debating KE, momentum, or penetration.
http://archeryreport.com/2011/02/bow-efficiency-care/
Yes I agree but starting at very different points (initial speed out of the bow) this initial difference in the bow give the advantage in KE to the lighter arrow, but as the graphs show the heavier arrow will pass the Lighter arrow in KE over time which equates to distance - so i believe with most set-ups out to say 40-50 lighter arrow still wins.
But look at the difference in momentum there is something to be said also about the ability for that to buffer outside forces such as wind, rain drops, etc. shows heavier arrow will not deflect off limbs t the degree of the lighter arrow. that could be important on an displaced shot.
as far as apples to oranges if the arrow, the material being penetrated and the tip the same this should be a fair test. mechanical broad-heads would have variance as they perform differently with different speed and KE.
Let's think about concept using bullets. A 7 RUM shooting a 160 bullet at over 2950 fps gives 3030 foot lbs of energy. Yet a 375 H&H shooting a 270 grain bullet at 2600 fps gives over 4000 foot lbs energy. Why? The 375 has more mass. Basically, heavier and slower will have a greater ability to do work i.e energy