Thats another thing, Why rely on the arrow to quiet the bow? Wouldn't you want the bow to be quiet from the get go that way you are not adding that as a factor into choosing arrow set up? Isn't that one of the things people look for in a bow is the noise level? I always have. Even my old bow. I bought accessories to quiet the bow.
You absolutely want the bow as quiet as possible from the "get go", but there's no such thing as silent bow. Some are more quiet than others, but they all make noise under the best of circumstances. I do not rely on my arrow to quiet the bow. It's an added bonus to shooting a heavier arrow. Being able to get rid of that heavy stabilizer that sticks out in the way is also a bonus. If your bow shoots quiet with a 350 grain arrow, it'll be whisper quiet with a 500 grain arrow.
The heavier arrow does not actually quiet the bow, it "absorbs" more of the bow's energy. The bow makes noise because it is expending all that extra KE that did NOT transfer to the arrow through vibration in the riser and limbs. A heavier arrow allows for more efficient energy transfer so there is less vibration. Now, you can buy a bunch of cool little gadgets to absorb tthe vibration or you can build an arrow to get a more efficient transfer of energy. Why buy an expensive,fast bow and then waste all of that available KE energy on vibration reducing gadgets? Me, I would rather have a heavier arrow and use the available KE to provide momentum for it. But, that's just my opinion .
I still want documented proof, video test, slow motion shots and a bunch of numbers to sort through. I guess that is just the engineer in me though.
I can understand that...others see you doubting, but honestly your mind just works with data no matter how much experience is talking. However I completely gotta agree with Bruce on this one, but for me I can just simply accept the common sense of it and do not need the data....sounds like you should do one of your experiments. I know I'd love to see findings *confirming Bruce haha!
Word. Perhaps you should practice what you preach. The ignorance is this thread is absolutely astounding.
Here you go, Stick. As I said, math isn't my strong suit, so I rely on others to do the math. http://archeryreport.com/2009/12/arrow-momentum-quick-reference-chart/ According to the chart listed at the web page above here's what I'd end up with on my two arrow combinations above: 400 grains total weight @ 300 fps = 0.533 slug* ft/s momentum 530 grains total weight @ 260 fps = 0.612 slug* ft/s momentum If this chart is correct, a 350 grain arrow would have to be moving at 345 fps to get to 0.536 slug* ft/s momentum, a comparable amount of momentum to the 400 grain arrow @ 300 fps, and they don't yet make a bow that can get a 350 grain arrow anywhere near my current set up's 0.612 slug* ft/s.
At this point ya all can argue it, hash it out all you want! What ever my new Destroyer 350 and full metal jacket 340s and 125 Shuttle T locks are generating for speed and KE ... are working like no other set up I have ever owned! Bone crushing energy and pass throughs. I have never been more pleased.
I'm guessing you didn't see the "" on that one. lol I would like to do an experiment. Not to prove Bruce wrong but, to prove how much more speed(velocity) a light arrow needs to penetrate the same amount as a heavier arrow. I have been running numbers. An arrow that weighs 350gr would have to travel 363.523FPS to have the same amount of momentum as an arrow that weighs 480gr traveling at 265fps. And yes Bruce they would have the same momentum. I have never said Bruce was wrong nor did I say that a 480gr arrow would have less penetration than a 350gr arrow. If the only variable that changes is in deed the weight, the heavier arrow will indeed have more momentum. Velocity staying the same that is. Now on the other hand if velocity increases on the lighter arrow the momentum will then increase. A lighter arrow will have to have much more speed than heavier arrow to get the same amount of momentum. As above shows, the lighter one will have to travel almost 100fps faster than the heavier one. Basically what I am saying is that if you have a faster bow you can afford to shoot a lighter arrow than if your bow was a good bit slower. Bruce is wright and so am I. A lighter arrow has to travle faster to have the same momentum. Given they are traveling the same speed or shot out of the same bow with the same setup, the heavier arrow will have more. Slower bows need heavier arrow than does a fast bow. My qestion of how much is enough still has yet to be determind and I don't think any of us are qualified to answer that one and every shot is different. It would take tons of data to find that one out. All in all its still the hunters choice.
I agree. I think everyone missed where I asked Bruce how much fatser a light arrow would have to fly to match the momentum of a heavier arrow and his answer was when they are sitting still. A light arrow can have the same momentum as long as it is flying much faster. This is one of the points I have been trying to make and it hasn't been seen by anyone else until now!!! Thank you!!!Never did I say a 350gr arrow would have the same momentum!!! only close KE.
Here is an attempt to explain momentum, I may not know what I'm talking about so check into anything I state for yourself. Momentum = mass X velocity Using the following set-up: Bow IBO Speed: 330 fps Draw Length: 30" Draw Weight: 70 lbs Added Grains to String: 20 grains Variable is weight of arrow, all this information I used to get an estimated speed of the arrow at different arrow weights using an online calculator ARROW ARROW MOMENTUM GRAINS SPEED GRAINS * F/S 300 340.00 102,000.0 320 333.33 106,665.6 340 326.67 111,067.8 360 320.00 115,200.0 380 313.33 119,065.4 400 306.67 122,668.0 420 300.00 126,000.0 440 293.33 129,065.2 460 286.67 129,065.2 480 280.00 131,868.2 500 273.33 134,400.0 520 266.67 136,665.0 540 260.00 138,668.4 560 253.33 140,400.0 580 246.67 141,864.8 600 240.00 143,068.6 620 233.33 144,000.0 640 226.67 145,068.8 660 220.00 145,200.0 680 213.33 145,064.4 700 206.67 144,669.0 With this set-up, if I'm correct, the greatest momentum is an arrow at 660 grains traveling at 220.0 fps, after that added weight no longer increases momentum. I've found some charts that change grains to slugs, a slug is equal to 225,218.34 grains, which is what you'd normally see momentum of an arrow expressed in. The real questions turns into how much is enough and that will always be answered personally.
I did read over it and maybe I am not explaining what I am trying to say clearly enough. I am still not saying Bruce is wrong!! The only thing that Bruce is wrong about is that a lighter arrow cannot have the same momentum no matter how fast it flyes. It can, maybe not out production bows we have but it can. That being said, I am done. I think.
Another way to express this at achieve equal momentum, for example. A 400 grain arrow shot at 300 fps has the same momentum as a 450 grain arrow shot at 267 fps has the same momentum as a 500 grain arrow shot at 240 fps has the same momentum as a 550 grain arrow shot at 218 fps has the same momentum as a 600 grain arrow shot at 200 fps. Now im confused, have a nice day, I need to get back to work!
Your math doesn't allow for distance or resistance. You are plugging numbers in that constitute an intance of time and don't even figure in resistance (the animal). The heavier object will retain more momentum over distance than the lighter object and will also retain more momentum when encountering resistance (the animal) than the lighter object. Also, as speed goes up, forgiveness goes down and, for hunting, I want a more forgiving setup. You are not the first guy to question all this stuff, just the latest. Do all of the experiments you want. I'll take this guys experiments and results over yours any day. http://www.alaskabowhunting.com/Ashby-On-Momentum-Kinetic-Energy-Arrow-Penetration-W19.aspx http://www.alaskabowhunting.com/Tech-Tips-and-Tuning-W3.aspx
