School me on arrows!!

[twintips16]

This will be my third year with a bow in my hands. Some of you might recal from my sight thread in the last couple days that i aquired a Mathews DXT and im in the process of setting it up. Im trying to leave my previous setup alone to enclude the arrows. I have tried to do a ton of reading but the choices are endless and the info is plenty.

Some people are trying to get the lightest arrow out there it seems. All the way down to light heads in order to drive speed up. When i read about this it always seems like there talking about whitetail hunting and i read very few posts about it in regards to elk hunting.

Then you have the people that are shooting heavy arrows and heavy heads to get penetration. Obviously they are not as concerned with speed.

Then i ran across weight forward arrows. What do these do for you? They dont change the overall weight so i can understand why having hte weight forward does anything for penetration even though that's why one guy told me he shoots them......

Does the type of broad head change what kind of arrow you want to shoot?

Im a 28.5 draw and plan on shooting around 70 pounds. Im thinking of using some slick trick 125gr magnums as my heads i think as i have read a lot of good stuff about these. What spline should i look at?

And finely we have helical fletchings. Im thinking that this helps put more of a twist on them in flight kind of like speeding up the twist in a barrel with heavy bullets, improving stabilization?

Im sure there is a bunch of opinions and i know i asked a ton of questions in one post, but try to bear with me as i try to pick this stuff up.

 

[SDHNTR]

Build a 400-460 gr total arrow with 12-15% foc. Shoot a 125 fixed head of your choice and you should be there already. At 28.5" or longer shoot a .300 spine arrow. You could use a .340 spine at 28" length or less. A Gold Tip Pro Hunter shaft in the proper spine would be about perfect. And yes, you want helical fetching. No question. Either short style Blazers/Max Hunters or standard 4" vanes. Personal preference.

 

[mtswampfox]

professional advice from a pro shop always works for me or my pals at deer crossing

 

[amp713]

If you want I can talk to you about each concern you have along the way, just shoot me a Pm and ill try to go piece by piece... If you want that is. Ive shot for a while and tinker all the time! Currently shooting with Deer Crossing Archery and can get you a discount through them also if you decide to go that route. I'm not only going to help you if you shoot their arrows so don't worry about that, Ill help you (to the best of my ability) with any arrow you are interested in....

Most of this is going to dial down to your own preferance and how/what you plan to shoot. If you plan to go after a bigger animal penetration is key so Kinetic energy is your best friend. Lots of ways to get there but a light arrow isnt really one of them. As for weight forward arrows they are.... Hype mostly. Or at least that is my opinion. A lot of extra money for arrows that I PERSONALLY didnt see a big difference in, Whatever arrow you decide to shoot i would shoot the stiffest spine possible, by throwing on a 125 gr broad head you can get a weak spine pretty quick. Better to be a little over spined than under. Depending on what you are after and how you want to shoot you could even use 100 grain broadheads and washers to add weight. That is the route I go as its easier to find 100 gr plus they 125's are usually built just a little bigger which i feel lets it plane a tiny bit better, if you dont need a bigger cut and are just after weight you can reach that a few ways.... Anyways there are a few thoughts.

 

[MakitaBoy]

Ive been shooting easton axis 400 for the last 6 yrs or so w a 100gr head for elk hunting i love them read some revises on them Ive never heard a bad one!

 

[doverpack12]

About the cheapest way to go and end up with arrows that will shoot very well is to shoot gold tip expedition hunters (these are exactly the same as XT Hunter and Pro Hunter other than the final straightness rating they receive before getting the grade paint/sticker and being packaged) and cut an inch off the back end of the arrow and the rest off the front. Get the 7595 spine rating I would then screw a 20 grain weight from gold tip or a socket allen screw from the hardware store to the back of the insert and use loc tite. Then use a 100 grain standard Slick Trick if those are the heads you like, (they are very very effective) and with the standard size you give up a little bit in terms of cutting diameter but you make significant gains in lack of wind plane and end up with a more forgiving setup. That combo will put you right at or just a little over 400 grains which I know alot of elk hunters who consistently kill elk like for weight up to 420 grains. For fletching all that is really necessary is 1* straight offset to stabilize a broadhead but helical is not a bad thing at all and can help in some situations it just creates more noise in flight (if you have ever stood down range you will know what I am talking about). For fletching there are tons and tons of options Blazers work really well and if you want to spend more or try some other options Flex Fletch and AAE Max Hunters are both good options. Personally I shoot Carbon Express Maxima Hunters (the weight forward you were talking about), I bought these originally when they used to be about the same price as 3-4 other equivalent options out there and stocked up and am still using that stock, I would not buy these at todays price tag, It makes no difference to me if the claims are hype or not because the arrows shoot great and are very tough. However I am an engineer and agree with the marketing hype they publish about dual spine and its positives.

 

[tipsntails7]

If you want I can talk to you about each concern you have along the way, just shoot me a Pm and ill try to go piece by piece... If you want that is. Ive shot for a while and tinker all the time! Currently shooting with Deer Crossing Archery and can get you a discount through them also if you decide to go that route. I'm not only going to help you if you shoot their arrows so don't worry about that, Ill help you (to the best of my ability) with any arrow you are interested in....

Most of this is going to dial down to your own preferance and how/what you plan to shoot. If you plan to go after a bigger animal penetration is key so Kinetic energy is your best friend. Lots of ways to get there but a light arrow isnt really one of them. As for weight forward arrows they are.... Hype mostly. Or at least that is my opinion. A lot of extra money for arrows that I PERSONALLY didnt see a big difference in, Whatever arrow you decide to shoot i would shoot the stiffest spine possible, by throwing on a 125 gr broad head you can get a weak spine pretty quick. Better to be a little over spined than under. Depending on what you are after and how you want to shoot you could even use 100 grain broadheads and washers to add weight. That is the route I go as its easier to find 100 gr plus they 125's are usually built just a little bigger which i feel lets it plane a tiny bit better, if you dont need a bigger cut and are just after weight you can reach that a few ways.... Anyways there are a few thoughts.

KE does not translate into penetration, momentum does, so yes a heavier arrow is better but KE itself is not an indicator of penetration. In my opinion DCA doesn't make a heavy enough arrow in the regular OD arrows that I would consider it a heavy arrow . Weight forward arrows I agree are hype, good FOC on the other hand is not. Fixed heads fly better with foc in the 13-16% range. Also if your bow is tuned broadhead planning won't be an issue either. I agree that being on the stiff side is beneficial because the arrow is less likely to be manipulated by shooter error. Washers in my opinion are a terrible idea, with the amount of components, heads and extra weights out there this is un needed and is just another piece that can throw of the spin of an arrow

To the OP if you have any questions regarding any arrow set ups I would be happy to run them through my software and tell you what it says, it's not gospel but it can get u pretty darn close.

 

[TheArtRed]

Hey guys. Just thought I'd put in my $.02 here.
Weight - In general, I look at the size game before I decide on arrow weight. The two things that contribute to penetration are the overall weight and smaller diameter. So in the south, I use the Deer Crossing Archery Hunter. Its a mid weight arrow that provides lots of forgiveness on range estimation but still has adequate penetration for whitetail and turkey. If I were to be hunting larger game (bear, elk, moose, etc) I would go for the SD Hunter. Heavier and thinner. I am really excited about our new 7075 Aluminum outserts. We will also have a stainless steel outsert available soon (finally allowed to talk about that one).

Spine - Make sure when you are picking your spine from the chart that you use your arrow length and not your draw length. If you are on the border between two spines, make sure you go stiffer. This is particularly important if you are shooting fixed blade broad heads. If the arrow OVER flexes, the glades become steering planes and will take the arrow off course. Also remember that adding more weight to the front of the arrow weakens the spine. Also, make sure to talk to your bow manufacturer or ProShop regarding your cam style for the spine chart.

Straightness - I'm not gonna lie. I'm not a big straightness guy. I always thought it was overrated. But there is an important bi-product of getting a straighter arrow. Most companies' arrows that are straighter will also have a more consistent spine. Less spine deflection means less tuning issues, particularly with fixed blade broadheads. I had to spine index my old .006 hunters for fixed blades. When I got my .003 hunters, I was able to shoot fixed blades with scary precision out to 40 yards. If you are going to shoot fixed, spend the extra money on a straighter arrow.

So I hope that helps. In retrospect, that was probably more like ten cents instead of two. If you have any questions beyond that feel free to ask. Whether its about Deer Crossing Arrows or just archery in general, I love to talk about the sport.

 

[sneaky]

Actually if you add weight to the rear of an arrow it STIFFENS the spine, not weakens it.

 

[amp713]

"KE does not translate into penetration, momentum does, so yes a heavier arrow is better but KE itself is not an indicator of penetration."

How do you figure? Kinetic energy is taking the mass of an object and its velocity to find out how much energy it is producing....... Momentum is taking the mass of the object and its velocity to tell you its momentum. The only difference is the way you add it all together but you are using the two EXACT same measurments. If anything KE is the measurement for how much momentum you have..... Not trying to make you look less inteligent or maybe I'm completely off my rocker, but I dont see how you are coming up with that statement?

Washers was just an example, I agree lots of ways to acheive what you want but i personally have never had a problem with them however I dont shoot them anymore since my outserts got me right close to where i wanted to be....

 

[amp713]

I decided to go ahead and verify this because I wanted to be 13438739847309% sure that I wasnt telling everyone a load of BS...........

Momentum: The equation to calculate momentum is simple: P=M*V, where P stands for momentum, M stands for the mass of the object and V stands for the velocity of the object. So, the momentum of an object is the product of its mass and velocity. If an object is not moving, it has no momentum.




KE: Step 2-Determine the mass of the object that is in motion. The mass of an object is the measure of how much matter is in an object.

Step 3-Determine the velocity of the object that is in motion. The velocity of an object is the speed of that object

Step 4- Multiply the object's velocity by itself in order to obtain the square of the velocity (velocity times velocity).

Step 5- Multiply the value you calculated in Step 2 (mass) by the value you calculated in Step 4 (velocity). You now have the kinetic energy of the object.


Get your grains and FPS and type them in whichever one you like but it doesnt change that those two are nothing but a mathmatical difference for measuring the exact same thing.....

 

[amp713]

Oh and Ill mention that step 1 was decide what you want to measure, and for there to be KE there must be movement.... Decided i didnt need to post it but dont want someone thinking i left out a step to make me seem right....

 

[OR Archer]

Amp your formula for calculating KE is missing a step. For archery the correct forumula is Mass x (velocity x velocity) / 450,240. This will give you your correct KE for an arrow.

Now saying momentum and KE are the same thing, well, they are not. Now to give you an analogy for the differences between the two. You could take a bowling ball and ping pong ball and set up some bowling pins. If you calculated the speeds to get the same KE between the two objects the bowling ball will still knock over more pins even though its slower because it has more momentum due to its mass which will make it harder to slow down. Now throw those two objects against a wall. You'll throw the ping pong ball a lot faster possibly producing more KE but that slower heavier bowling ball with its greater momentum will go through it while the ping pong ball will bounce off. Granted there are still other variables to be considered but this is a pretty simple explanation of why KE is not a good judge of penetration.

 

[sneaky]

KE is the amount of force required to stop an object over the span of one foot. Momentum is the amount of force required to stop an object over the span of one second. Like a wiffle ball and a softball. Sure the wiffle ball will be quicker at 100mph but the 50 mph softball will hit harder and inflict more damage. Heavier arrow stores more energy at all ranges as well and makes your bow quieter. KE is an advertising gimmick. Big MO is the real deal.

 

[OR Archer]

KE is the amount of force required to stop an object over the span of one foot. Momentum is the amount of force required to stop an object over the span of one second. Like a wiffle ball and a softball. Sure the wiffle ball will be quicker at 100mph but the 50 mph softball will hit harder and inflict more damage. Heavier arrow stores more energy at all ranges as well and makes your bow quieter. KE is an advertising gimmick. Big MO is the real deal.

^^^Yep!

 

[tipsntails7]

For the record. A joule is a measurement of KE, and a joule is ENERGY. One joule will be expended while applying the force of one Newton over the distance of a meter. KE also does not have a directional value because it is pure energy. Energy that begins to expend as soon as PE turns into KE. As an arrow is met with air resistance while flying and then hitting a target, Momentum is not an actual, physical value, but it is a representation of values (velocity times mass) that is useful for engineering calculations. Both are useful, though very different, yet integrally tied together.

All of this is while working with velocities under the speed of light. Above that things get "weird"

KE= knock down power
Momentum= penetration

You are off your rocket

 

[OR Archer]

For the record. A joule is a measurement of KE, and a joule is ENERGY. One joule will be expended while applying the force of one Newton over the distance of a meter. KE also does not have a directional value because it is pure energy. Energy that begins to expend as soon as PE turns into KE. As an arrow is met with air resistance while flying and then hitting a target, Momentum is not an actual, physical value, but it is a representation of values (velocity times mass) that is useful for engineering calculations. Both are useful, though very different, yet integrally tied together.

All of this is while working with velocities under the speed of light. Above that things get "weird"

KE= knock down power
Momentum= penetration

You are off your rocket

You straight got your nerd on with that post haha

 

[avodude]

Those are great analogies OR Archer and sneaky.

Here are the equations for KE and Momentum, next to each other, if anyone is interested (nerd alert!):

KE = .5*m*(v^2) - emphasis is on velocity as it is a squared value. Explains the trend toward a lighter, faster arrow if you are going for a greater KE
P = m*v - equal emphasis on mass and velocity. Mass of the arrow and the speed of the bow are proportional to each other.

Drag can also play a part and the equation for that is:

D = Cd * A * .5 * r * V^2 , D = drag force, Cd = ignore this term(assume light and heavy arrows have the same shape), A = cross-sectional area, V = velocity, r = density

Once again, velocity is squared in the drag equation and therefore has a greater effect on the drag force than any other variable. The faster you go, the greater the drag force.

Add to this that a heavier arrow has more inertial force (it is more difficult to slow down). So KE can bleed off pretty quickly for very light, fast arrows and add to that that bows are more efficient at transferring their energy to a slower arrow than a fast one.

Problems also arise when the KE is converted to work after a collision as some of the KE is lost to sound (thwack) and heat(friction).

What it amounts to is that the heavier, slower arrow will actually "fly" better, through the air, than the light fast one delivering more of its initial energy down range to do the work of penetration/cutting. Momentum may not actually play that big of a part here. This is similar to comparing small-bore and big-bore rifles and the resulting down-range energy. Momentum doesn't play that much of a part there either.

 

[amp713]

So I've tried to type dozens of replies but i think the best i can do is just to say that Ive always seen the world differently than those around me. Each reply turns into something I dont think others would understand.... Its always been hard for me to explain how stuff relates in my head though. One of the reasons I had so many issues with college classes and proffesors hahaa....

Reading all of your guys posts (and they make perfect sense to me) I see it almost like you guys are telling me the same thing just with different wording. I think you all see me as being way off (and my equations were off so ya i get that) but I just see us all agreeing from a different explanation. I used to try to explain the way it works in my head but it just makes a bigger mess so I will say that I'm agreeing with the thought process while not totally agreeing...

And if you are throwing ping pong and bowling balls at walls I would like to join, demolition is one of my favorite parts of house work!

 

[SDHNTR]

this is simple.

KE measure force AT impact. Momentum measures force that will be retained AFTER impact.

For the purpose of archery, momentum is more important as an arrow kills by penetrating into the vitals and cutting tissue. That happens after impact. An arrow does not kill by force at impact (like a bullet). As was said earlier, you can make a lot of KE with a light and fast arrow, but it dissipates a lot of that energy upon impact. A slower, heavier arrow retains that energy after it hits and allows it to do its job.

You could almost throw KE out the window. It's a worthwhile figure for gun hunting, but mostly worthless for bowhunting.