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Extreme f.o.c or heavy arrow
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Originally posted by cbd10pt View PostI killed 14 hogs and a buck this year with a 383 grain arrow 13% foc
Rage ss broadheads 55# bow 285 fps
The ones you hit right die
The ones you don't - not so much
Slow ars arrows tend to cause more bad hits.
Fast arrows with big fixed blades cause more bad hits.
I've been on over 300 blood trails , all kinds of heads/arrows/speeds etc.
Just make sure you hit them right
Originally posted by enewman View PostIkemanTX
here is a few numbers for you.
Arrow 1 400gr. .520 momentum
Arrow 2 600gr. .520 momentum
Which arrow will out penetrate if all other factors are equal. Now this is a physics test. So, bone in not part of the equation.
The question and test will show you if this statement made by most is true or false. ( momentum built on mass will out penetrate momentum built on velocity)
The test will also give you the answer if it’s ke or momentum that gives us the capacity to penetrate.
Bone HAS to be part of the equation because it is a probable obstacle in bowhunting. If you’re building a setup ignoring limiting factors, you are designing your own failure.
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Originally posted by enewman View PostOf course it did. Question is, would a 550 have done the same?
550? Most likely. I wouldn’t be surprised if the only difference between my 710 and 550 is the broken femur not happening.
Now, I know a 350 grain wouldn’t have done it. I’ve shot enough of those in the past to know that the amount of bone and hard cartilage my arrow went through would have stopped it cold.
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Originally posted by IkemanTX View PostIf these were stoic, stationary targets…. I would halfway agree. It has been proven time and time again that a whitetail can drop more than 7 inches from arrow release to impact, even with a fast bow. “Hit them right” is only the plan A. I will always aim for plan A, but I want enough penetration and breaking power to make it through plans B, C, and D if the unfortunately happens too.
Bone HAS to be part of the equation because it is a probable obstacle in bowhunting. If you’re building a setup ignoring limiting factors, you are designing your own failure.
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So, answer the question. It’s a physics question.
Projectile 1 is 400gr at .520 momentum at impact.
Projectile 2 is 600gr at .520 momentum at impact.
Which projectile will be harder to stop.
We can add the variables back in after you answer the question.
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Originally posted by enewman View PostNo sir. You are not answering the question. You are wanting to add a variable. To test physics we remove variables. But let’s talk about bone. I’ve killed a range of animals over the years. Around 100 plus not counting turkey. To hit bone is around 3 to 4%. Now that is major bone. Those are low odds. Why are my odds low? I don’t take shots that are questionable or I try not.
So, answer the question. It’s a physics question.
Projectile 1 is 400gr at .520 momentum at impact.
Projectile 2 is 600gr at .520 momentum at impact.
Which projectile will be harder to stop.
We can add the variables back in after you answer the question.
The “variable” is an integral part of the physics question. It is a part of the minimum performance requirements. It doesn’t matter if the 380 grain arrow penetrates ballistic gel ever so slightly better at the matched KE if ribs are a potential (more accurately probable) interaction, and especially since all it takes to hit a scapula is a jumpy deer…
As to which projectile will be harder to stop… it depends on the type of stopping force. There are frictional, virtual mass loss, rotational inertia loss, and impact loss to all be accounted for in unknown percentages when hunting deer. Target shooting is almost exclusively frictional loss, which performs better via KE.
Heavier arrows also tend to have higher KE out of a specific bow, and they shed velocity more slowly flying through the air (they penetrate the air better!) leading to higher KE's down range. Which also changes the equation.
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[quote=IkemanTX;15686841]The “variable” is an integral part of the physics question. It is a part of the minimum performance requirements. It doesn’t matter if the 380 grain arrow penetrates ballistic gel ever so slightly better at the matched KE if ribs are a potential (more accurately probable) interaction, and especially since all it takes to hit a scapula is a jumpy deer…
As to which projectile will be harder to stop… it depends on the type of stopping force. There are frictional, virtual mass loss, rotational inertia loss, and impact loss to all be accounted for in unknown percentages when hunting deer. Target shooting is almost exclusively frictional loss, which performs better via KE.
Heavier arrows also tend to have higher KE out of a specific bow, and they shed velocity more slowly flying through the air (they penetrate the air better!) leading to higher KE's down range. Which also changes the equation.
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I guess I will answer the question for you. Now I’m doing this on my iPad so my spelling my not be good, please bare with me.Last edited by enewman; 07-03-2021, 03:28 PM.
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Originally posted by enewman View PostSo, while you are beating that dead horse. Take your hand at answering the physics question I asked.
Projectile 1 400gr .520 momentum at impact
Projectile 2 600gr .520 momentum at impact
Which projectile will be harder to stop.
you have added a variable and expect an intelligent answer??Last edited by Tom; 07-03-2021, 03:42 PM.
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I think the point is a lot of bias going on. Do what works for you...Sure you lose some feet per second on speed but you gain a lot more penetration if you hit ribs or scapula. That is a fact the heavy arrow will penetrate more than the lighter arrow. Anyone can test that theory with a simple target in their backyard.
You want a flat projectory go for it. Your opinion and wants/needs. I like the heavy arrow, maybe I will change but right now it is a lot of fun slinging a 560 gr versus my old 380gr and quieter.
The ranch fairy did test a 380 gr arrow as well. It is in the notes and talked about in the second video. The rocket scientist explains physics and breaks it down. I am going to trust the guy that has been doing this stuff for 20 plus years and has no bias versus a guy that is youtubing how to do physics and is biased on getting his fast arrow results.
Have we all killed deer with a 380 gr arrow or a pig...yes. Most of my arrows from a tree stand didn't penetrate. I usually hit the off shoulder or leg or something. However, with a 560 gr arrow it has yet to fail to penetrate no matter what and I have shot a lot of pigs at a lot of angles. Common sense tells you that their is more energy behind the arrow that is heavier despite it going slow. Shoot a target with both arrow setups and see which one goes deeper
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Ok projectile 1. 400gr .520momentum. 225218*.520/400=292.78fps. .5*400*292.78^2/225218=76.12ke
Projectile 2 600gr .520 momentum 225218*.520/600=195.19fps. .5*600*195.19^2/225218=50.75ke
In physics (before you add all the variables you keep adding haha) states unequal mass, equal momentum the object with the highest velocity will be harder to stop. That object will have the highest amount of Ke.
This statement in physics tells you what gives us the ability to penetrate. It’s not momentum. It’s KE. To test that you can shoot those two set ups into any consistent medium. Again we are talking about physics not hunting.
That was an easy answer to my question. It is not momentum.
If we look at work. Work is the change in KE. Next we look at force. So how do we calculate Force. F=w/d. W is change in ke and d is distance.
Now let’s add bone as you keep wanting to. When we look at breaking bone we look at mass not momentum. We need to look at impulse. Now dr ashby talks about time of impulse. ( no such thing) It’s just impulse. We also need to look at inertia.
Impulse you want to be as short as possible. The longer the impulse is the less chance we have in breaking the bone. So, why does a heavy break bone better. Because the bone breaks before the inertia of the weight gets below the level it takes to break that bone.
Now, can we break bone with a light arrow. Absolutely. We must now go back to looking at ke. A 600gr May break bone at say 50ke but it might take the 400gr 100ke. So why do we shoot heavy, because most of us cannot get enough ke for the light arrow to do the job.
Again just because we can’t reach the level needed dosent mean ke is not what gives us the ability. We just may not get there.
I have another physics for you. Did you know in physics it tells us that Two objects with equal ke and unequal mass if the retarding force is equal they will penetrate the same. That means a 400gr at say 75ke with .516 momentum and a 600gr at 75ke with .631 momentum will travel the same distance. Remember I said equal retard force.
This test I have seen by Dave holt.
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Originally posted by Tom View Postbad comparison. These two projectiles did not come out of the same bow at the same distance.
you have added a variable and expect an intelligent answer??
But since you have an issue with it. Let’s ask the question another way
Shooter one is shooting a 400gr at .520 momentum into an equal retarding force medium.
Shooter two with a different bow is shooting a 600gr arrow with .520momentum into an equal retarding force medium. Who will have the greater amount of penetration. Shooter 1 or shooter 2?Last edited by enewman; 07-03-2021, 04:09 PM.
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440-510 grains perfectly tuned 280 fps. Don’t give two ****s about foc. The people who say high foc is more accurate don’t know what they are talking about. You can ask Tim gillingham, Levi Morgan or a number of other pro shooters who are literally the best in the world at getting arrows to fly. Tim won IBO worlds with like 65-75 grain nibs one year.
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Originally posted by JTeLarkin08 View Post440-510 grains perfectly tuned 280 fps. Don’t give two ****s about foc. The people who say high foc is more accurate don’t know what they are talking about. You can ask Tim gillingham, Levi Morgan or a number of other pro shooters who are literally the best in the world at getting arrows to fly. Tim won IBO worlds with like 65-75 grain nibs one year.
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but I will give you a test to prove that FOC does stabilize an arrow. Of course all you need to do is read on center of gravity and center of pressure and it makes the pros look stupid.
So here is your test. Build a standard foc arrow. 12%. I want you to shoot it bareshaft with a 1.5” wide to blade. At 20 yards. Then build you one around 25% and shoot same broadhead bareshaft. You are going to see what FOC does for you. Again it’s simple Aeronautics . Just read.
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Originally posted by enewman View PostFoc is for flight. Not penetration on a compound bow. So I agree, but go ask Tim and Levi what broadhead they are shooting. I know Tim doesn't shoot fixed. So, unless you shoot a big wide fixed broadheads that causes lift. Then you don’t need to worry about FOC.
but I will give you a test to prove that FOC does stabilize an arrow. Of course all you need to do is read on center of gravity and center of pressure and it makes the pros look stupid.
So here is your test. Build a standard foc arrow. 12%. I want you to shoot it bareshaft with a 1.5” wide to blade. At 20 yards. Then build you one around 25% and shoot same broadhead bareshaft. You are going to see what FOC does for you. Again it’s simple Aeronautics . Just read.
Tell that to all the arrows witg 12-16% foc I have made over the years that shoot fixed blades to 100 yards [emoji849]
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