I see quite often on the arrow components forum a request for heavy points. Some even up to 250 grains?
Why? What do you think is the advantage?
The times I tried anything heavier than 160 gr they dropped like rocks! I prefer 125 gr and even 100 gr with light shafts.
Energy = mass times velocity squared
It is better to keep the speed up and the points sharp - you will have more energy on impact and with sharp points, good penetration. And the arrow will fly a flatter trajectory.
No intention of startng a ruckus here, but I would like to know what you think. I would also like the science more than the opinion here as well.
Simple version: Volkswagon and a desiel truck doing 60, both hit a brick wall. Which one is going to make it through the wall?
Trajectory with the way we shoot is a non issue. If you pratice with a heavy arrow your brain learns the trajectory and becomes a non-issue, now if you pratice with a light arrow then switch the weekend of the season then you have a problem
I try to stay around 10 to 11 gpp its just the trajectory my brains is used to.
Some use a lighter arrow and a heaver point to get the FOC up.
A lot of info on this in the Ashby reports.
do some searching on FOC.
Realize the energy formula you're using gives you a figure that really doesn't pertain to the way an arrow uses energy to penetrate.
Just use a simple inertia formula...wt x speed.
wtpops has a good point...but...some bows might be able to get that "VW" arrow going 60mph but can't get the "big diesel" going 60mph. so the question ends up being more like a VW going 60 and a truck going 40...hard to figure in your head right.
SO...you need to figure is it better to have a lt arrow going faster or heavy going slower....just as you questioned in your post.
Don't double the speed in the energy equation it just gives a number that doesn't pertain to what we care about.
if possible...Take a heavy arrow that shoots straight out of your bow. I mean a heavy total arrow. at least 13grns/# hopefully more.
Then find a lighter arrow that shoots straight 10grn/# or less.
Shoot them into something side by side. Something that'll not have voids or give much..like a new block target or something. If you really want to see a difference suspend the target so it swings.
You'll hear a diff when the arrow hits.
You WILL see a movement diff and/or a penetration difference.
Here is a REAL example from my bow and my chrono.
(http://i748.photobucket.com/albums/xx121/Zradix/Screenshot2011-06-30at115021AM.png)
Guess which arrow I use?
Hint..568 grn.
Also. if you do any reloading think about sectional density being important...not so much ft/#'s. our arrows aren't blowing up inside the animal to use up energy...just passin thru.
Fun stuff!
Zardix, explained it a lot better, here are my numbers using his formula. this is a brand new set up im trying out. ft/sec is acording to Stu's calculator i have not ran this set up through a crono but with experence with other setup it looks to be very close.
Arrow # 628
ft/sec 180
wtXspeed 111,600
#draw 56
gpp 11.2
FOC 18.2%
ft/pounds 45.1
None of this means a hole lot except to those who likes to tinker of which i am one but i can tell you this setup hits a lot harder than any of my other setups. Benman Classic MFX with 250 up front
John, I used to wonder why most trad folks shot heavy points. I shoot very light poundage 50 lb bows and like you didn't like seeing my arrow nose dive out at extended yards. FOR ME this was mainly on the 3-D course though. Our hunting shots here in the east are mainly inside 15 yards from trees and the drop really isn't an issue at those yardages. So I made the move to the masses. I will tell you that the penetration factor for the heavier setup over the lighter is the way to go on our deer. Now your shots out West can be much longer and you will have to make your mind up to go heavier but I would suggest you give it a go.
John:
Your analysis is spot on.
Many trad archers have the idea that super heavy arrows are superior. Personally, I've not been able to demonstrate that, even though I've spent some amount of time trying.
So, keep on shooting the arrows that work best for you, and don't get too worked up about all the cross-talk on heavy arrows or high FOC because none of that stuff is substantiated by evidence that is reproducable.
Here is somthing i found on a sponsor web site.
The formula for momentum calculation is:
"Momentum = mass multiplied by velocity or p = (m)x(v)"
(Note: You ask why P stands for momentum? "The symbol P for momentum comes from the original term used to describe persistence of the object's motion" )
The term "Persistence" describes how we want our arrow and broadhead to perform. Momentum or Persistence is what drives the arrow and broadhead into the animal. Momentum being the combination of arrow weight and velocity is what propels the arrow through the hide, tissue and bone. This is why Momentum is more meaningful to the bowhunter than Kinetic Energy. Going back to the formula for momentum we see that velocity plays a part but is not more significant than mass. From this we can conclude that if the velocity is kept constant and the weight of the arrow is increased the momentum (P) of the arrow is increased proportionally. This is good news particularly for the traditional archer. The traditional archer can concentrate on arrow mass which is easily controlled or varied rather than on velocity which generally can only be increased by shooting heavier draw weight bows. By increasing arrow weight or mass we can see a significant increase in Momentum (Persistence) and increased penetration potential. This opens up a new world in arrow design. We can study and experiment with "forward of center arrows" (FOC),"extreme forward of center arrows" (EFOC) and "ultra extreme forward of center arrows"(Ultra-EFOC).Remember the ball analogy; the heavier baseball does more damage on impact. The heavier slower arrow has more momentum (P) than the lighter arrow, and thus does more damage on impact and has persistence to penetrate. Summing up, calculations of KE for a light fast arrow may indicate high kinetic energy (KE) but will have a relatively low momentum (P) compared to a heavier arrow traveling at a slower speed.
Momentum (P) and Kinetic Energy (KE) along with weight forward of center arrows (WFOC) are being considered by more and more archers as they become educated and convinced that arrow speed alone does not kill!
As said above shoot the arrows that work best for you!! But you asked the question so we will try to help you with the answer and you make the choise that works for you.
Also as you can see buy Zradix chart there is a point in arrow weight where to much is not good also.
I dont have any science but common sense tells me that if you are concerned about arrow penetration shoot a heavier bow.If you cant shoot a heavier bow workout until you can.As far as arrow weight goes its just like my dad would say where theres a loss theres a gain and where theres a gain theres a loss.You can only crunch number so long before you have to shoot a heavier bow to make an arrow shoot harder.
QuoteOriginally posted by park:
I dont have any science but common sense tells me that if you are concerned about arrow penetration shoot a heavier bow.If you cant shoot a heavier bow workout until you can.As far as arrow weight goes its just like my dad would say where theres a loss theres a gain and where theres a gain theres a loss.You can only crunch number so long before you have to shoot a heavier bow to make an arrow shoot harder.
Park is right on, always shoot the heavest bow you can with out overbowing your self and efecting form but once you reach that point you can play with your arrow and help too.
With all this said if you do not like to tinker ,some do and some dont, just shoot what works for you after all we dont hunt elephants here in North America.
Penetration!...........♠
:biglaugh:
I love getting into the science and math of all this, because it is fun. But basically there is only one formula you need to know:
Arrow flying straight and accurate, from a bow with at least 40 lbs. of pull, and a razor sharp BH on the front = dead deer.
Fought heavier arrows a good while in favor of liteweights for speed. Zero question heavier arrows w/sharp bh will outpenetrate especially through bone. Find something you can live with. 750gr arrows are sleight light for my setup. But they're flat shooters.
I shoot heavy points because I get better penetration with EFOC shafts. I shoot GT 55/75 with a 50gr brass insert and 200gr muzzy phanton up front. Total arrow weight about 540grs. I don't think this is a "heavy" arrow.
QuoteOriginally posted by GO Rogers:
Penetration!...........♠
Short and sweet. I like it :notworthy:
As far as the heavt arrow argument goes you will have to experiment and see what works best for you. Faster isn't always better if it just bounces off when it gets there. On the same token, as you go heavy there will be a point of deminishing return. A 1500 grain arrow isn't going to do a bit of good if it doesn't move fast enought to penetrate. Each set up will have it's own specific bell curve for oreformance with different arrow weights. As a general rule of thumb around 10 grains of arrow weight per pound of draw weight is a good place to be. As far as the heavy point instead of overall arrow weight goes, your arrow will fly and penetrate better with more weight up front because the forward mass "pulls" your arrow through the air rather than your arrow being "pushed" by an arrow that is perfectly balanced or even tail heavy. Sometimes people just order heavier points because it's a simpler way for them to get an arrow rough tuned or in my case I cut my arrows too short and had to have a heavier point because I didn't want to throw out a brand new dozen. :banghead:
Gives you better "chance" on bloody pass through when a lousy shot has been made. On deer, turkey, b. bear, and -250lb hogs, why loose the trajectory. 475-525g arrow humming right along. I've had miserable results with 700g efoc set ups, wouldn't penetrate a hog shield to save my life. They were bare shaft tuned to 30yds, just food for thought.
I shoot a heavy point for the extra FOC it gives me. I believe that the Ashby data is very conclusive on this, However I only am able to hunt whitetail and hogs, so I do not make up 700 grain arrows for my 55 pound bow I find that an arrow around 600 to 650 grains with 15 to 20% Foc works best for me.
Read thru the Ashby reports, this one has been proven and resolved in full. Higher mass with efoc = increased penetration.
most of this stuff is just icing on the cake....after you learn how to shoot accurately, tune an arrow/bow combo and learn how to get a broadhead sharp.
You don't NEED 13grn/# and high foc to kill stuff.
But the above might help in a not so perfect situation...I like to hedge my bets.
I also like tinkering with stuff...many don't
QuoteOriginally posted by Bobaru:
John:
So, keep on shooting the arrows that work best for you, and don't get too worked up about all the cross-talk on heavy arrows or high FOC because none of that stuff is substantiated by evidence that is reproducable.
There are a couple of people around who actually make a living guiding hunters on Big Game whose real world life experience would say different .
To dismiss years of field work and experience with such flippancy without at least field work to show otherwise ... :dunno:
I don't shoot EFOC arrows as the game I shoot is considered light skinned medium sized game . The original idea , I believe , behind the EFOC testing / theory was for the hunting of large boned, heavy , thick skinned big game .
The testing began because of poor results being acheived with 'light' equipment / arrows and even flimsier broadheads as the quest for speed etc gathered attention.
the EFOC argument was never directed at people hunting 150lb whitetail deer , although the same principle may be applied to good , if perhaps uneeded , effect on thin skinned North American game.
I also believe it is also a product of carbon arrows , which in the past have so often been very light in physical weight that the heavier heads allowed the use of carbon shafts that could now weigh in the more accepted weight ranges [9-11gpp] without the use of weight tubes etc .
QuoteOriginally posted by Ben Maher:
QuoteOriginally posted by Bobaru:
John:
So, keep on shooting the arrows that work best for you, and don't get too worked up about all the cross-talk on heavy arrows or high FOC because none of that stuff is substantiated by evidence that is reproducable.
There are a couple of people around who actually make a living guiding hunters on Big Game whose real world life experience would say different .
To dismiss years of field work and experience with such flippancy without at least field work or evidence to disprove otherwise ... :dunno:
I don't shoot EFOC arrows as the game I shoot is considered light skinned medium sized game . The original idea , I believe , behind the EFOC testing / theory was for the hunting of large boned, heavy , thick skinned big game .
The testing began because of poor results being acheived with 'light' equipment / arrows and even flimsier broadheads as the quest for speed etc gathered attention.
the EFOC argument was never directed at people hunting 150lb whitetail deer , although the same principle may be applied to good , if perhaps uneeded , effect on thin skinned North American game.
I also believe it is also a product of carbon arrows , which in the past have so often been very light in physical weight that the heavier heads allowed the use of carbon shafts that could now weigh in the more accepted weight ranges [9-11gpp] without the use of weight tubes etc . [/b]
QuoteOriginally posted by john fletch:
.................No intention of startng a ruckus here, but...........
:clapper: :laughing: :rolleyes: :deadhorse:
Whatever......you're kidding, right?? Good one man!
I like EFOC for the better penetration and excellent arrow flight.
Read the Ashby reports or at least read his article in one of the older Traditional Bowhunter Magazines.
Ben, I hear what you say. But, I disagree. First, Ashby maintains his work is not scientific. Second, nobody can reproduce his results because his work is not scientific.
This is probably not politically correct on this forum, but I discount Ashby's work for two reasons: (1) Ashby does not attempt to control all the variables except those which he desires to measure which seriously limits any results (2) Ashby then puts together slick graphs which imply a measure of accuracy and certitude which I'm certain his basic data never justifies, yet he never mentions this (meaning his stuff is similiar to the laundry detergent commercials that promice "30% more better" something or other.
Other than Ashby, I haven't seen all the research you're talking about. Sorry.
If it does exist I'm more than willing to take a look.
In the meantime, I've run my own tests on the arrows which will fly out of my bow and have determined which arrows have the best penetration. And, while Ashby claims to have spent over $ 300,000 on research which is not scientific, the work I've done for myself is sufficiently scientific to satisfy myself that EFOC arrows are not a worthwhile venture for me.
You can shoot whatever arrows you want for what ever reason you want.
Have a good day.
I don't think Ashby said that his work was not scientific but please point out to me where that is.I could easily be wrong.Watching a video recently where he gave an introduction to the study,sounded like he said the opposite.All that may be getting a little off the original question.
Regarding heavy point weight though,O.L.Adcock set at least 3 World flight bow records using high FOC arrows.He and I believe Bob Morrison got Ashby interested in the concept back when Ed Ashby didn't think it would be important to his studies.He has since changed his mind based on what he has found.
As of 2009 at least,it looks like 2 of O.L.'s World flight bow records still stand and my understanding is,the one that was broken,was done so with high FOC arrows.The theory used to be that a light front end on the flight arrow would keep the point up and it would go farther.O.L.,a flight engineer,did something to change that thinking.
QuoteWith all this said if you do not like to tinker ,some do and some dont, just shoot what works for you after all we dont hunt elephants here in North America.
Due to a shoulder injury during a past deployment, I am shooting a max weight of 47#. My bow is 62", 47# @ 29". FF string and cut to center. I played around with a bunch of different combinations yesterday and the best flying arrow was GT Hunter 3555's cut 30" bop tipped with 125gr field tips. Total arrow weight of 384gr.
Now, I'm only using this bow on Blacktail deer. I will be using a Steel Force Phat Head 4 blade broadhead 125gr. This arrow seems a little light to me but, I can't argue with the way they are shooting and I'm nailing my grouping. Never shot a deer yet so, what are your folks thoughts? Will I be good at this light of an arrow?
(http://i415.photobucket.com/albums/pp233/TradNut/101_0587.jpg)
Spot on target!!! :bigsmyl: :thumbsup:
Here is what I know to be true and it has been gained by losing a few animals I need not have lost.
Light arrows shed their energy much quicker than heavy arrows. The entire goal of a broadhead tipped arrow is to enter, slice and exit - doing the most damage it can make and leaving a blood trail we can follow.
Light arrows will work great when the shots are perfect, and when they're not perfect? You will suffer lost animals for it.
you can do something else too ........ watch Real Tree and similar videos and about 1/2 the animals shot with very high powered compounds (and high KE setups) get horrible penetration because they're using light arrows and mechanical heads.
2 and 3 years ago I shot a 51# @ 27" Zipper, weighted carbons and 225 gr Steel Force single bevel heads. 2 shots, 2 passthrough. Not a lot KE in that setup. Last year I went to wheels, lighter arrow, much higher KE and didn't get a passthrough (though I did recover the deer the next afternoon due to determination and luck)
I believe 100% had I been shooting my heavy arrows and 51# Zipper and Steel Force heads I'd have passed through that deer those light arrows and 4 blade head failed to.
JMHO
Seems a bit light to me.
8.17gn/# may well void any warranty.
Might work on a deer...I'd say get close.
If it were me I'd experiment with some heavier arrows just to be on the safe side.
You might like the way it'll tone the the vibes/sound.
Again you might be just fine.
Sure is a nice looking bow. sorta short riser-long limbs. Bet it's smooth!
QuoteOriginally posted by Wannabe1:
QuoteWith all this said if you do not like to tinker ,some do and some dont, just shoot what works for you after all we dont hunt elephants here in North America.
Due to a shoulder injury during a past deployment, I am shooting a max weight of 47#. My bow is 62", 47# @ 29". FF string and cut to center. I played around with a bunch of different combinations yesterday and the best flying arrow was GT Hunter 3555's cut 30" bop tipped with 125gr field tips. Total arrow weight of 384gr.
Now, I'm only using this bow on Blacktail deer. I will be using a Steel Force Phat Head 4 blade broadhead 125gr. This arrow seems a little light to me but, I can't argue with the way they are shooting and I'm nailing my grouping. Never shot a deer yet so, what are your folks thoughts? Will I be good at this light of an arrow?
(http://i415.photobucket.com/albums/pp233/TradNut/101_0587.jpg) [/b]
I would look for a different 125 grain BH. That one does not look like a great one for penetration on a bone hit. I would wnat more arrow weight, but I like about 10-11 GPP so I am in the other camp. At that bow weight and set up, I would want as close to 3:1 as possible. IMHO
Penetration=recovered animal. That has been studied in several wound loss studies of bowhunters. Find what penetrates the best and you can shoot accurately.
Try a couple other weight arrows and broadheads and MEASURE the penetration you get in that target. If you can get an arrow to penetrate better and fly as well,.....
Ok, so I tried an Arrow Dynamic Trad Lite. Cut 29.5" bop with a 175gr field tip. Total arrow weight on my scale is 495gr. They flew pretty well but, looks like they are hitting the outside edge of my shelf. Need to raise nock? Penetration was awesome as it went through the block target and a little styrofoam target behind it and into the plywood. No joke! But, hitting the outside edge of riser worries me.
Wannabe1, If your are hitting the outside edge of your shelf you are probably still too stiff. I would go with a 200 or 250 grain head and see how things fly.
Personally, I shoot 300 grains up front (610 grain total arrow weight) out of a 51 lb bow. I have had the arrow sticking in the ground after every deer shot with this combination - which is my goal. I used to shoot about 470 grains total arrow weight out of a 60 lb bow and had occasional penetration problems and never had the arrow leave the deer (though usually had entry and exit holes). I have had problems recovering 3 deer using that combination. All were due to poor penetration on shoulder area hits. When someone says they have a method that will increase penetration I listen and test for myself. I know heavier arrows work and believe high front of center helps.
Hot Digiddy Dog! I think I finally got it! Beman MFX Classic 500, cut 30" bop, 75gr insert w/175gr tip for a total arrow weight of 556gr. Flying like missiles and hitting hard and penetrating deep! No sign of hitting the shelf edge. Can't use the shaft I originally wanted but, a humane kill is more important too me. Thank you all for the help and tips.
John, please forgive me if it seemed like I hijacked your thread. I just needed the help to get this bow in tip top shape for hunting season. :D :thumbsup:
Excellent job Wannabe 1
What you have accomplished with your tuning is what I too spend countless hours doing with great satisfaction! There is no end to how you can change things up..don't be surprised when down the road you surpass the efficiency of this setup as well! I love when we find things out for ourselves, that is the most reinforcing feedback we can get.
Best of luck and keep experimenting (***WARNING*** tuning traditional bows can be addictive).
Kris
This is why my new carbon arrows are about 8gpi instead of the 10 and 11 in some 400 spine arrows. I can have my cake and eat some of it. I'm saving 65-85 grains in weight in the arrow and switching that to the point, and still will be shooting close to 10 gpi with 275 up front.
Testing on live subjects hopefully will be conducted in about 4 months. :D
Ok, so here's a pic I just shot of a MFX Classic 500 w/250gr up front. The setup I described above. I pulled the arrow out a little so you could see the tip. It completely penetrated both targets, 1 sheet of 1/2" treated plywood and 1/4" into the second sheet. Will this work?! :D
(http://i415.photobucket.com/albums/pp233/TradNut/101_0589.jpg)
High speed photography shows substantial arrow flex upon impact. Concentrating the weight in the head transfers the weight to the target/animal instead of being wasted in the arrow flex.
:campfire:
I hunt primairly Whitetails and I shoot heavy arrows Hunting and for 3d the same setup 75/95 GT's 100gn brass insert 300gn Head with weight tubes in the shaft coming in at 1078gn's out of a 80# longbow seems a little much for a deer but remember there is no such thing as overkill :goldtooth:
heavier arrow means more penetration. archers want momentum. arrows kill by penetrating vitals. now with a gun KE actually means something, but ke and archery really dont mean much.
i shoot 250gr points on my arrows because i need that to get my arrows to work for my bow, and it allows me to ge tthe hunting wieght i want. arrow flys great to 30 yds and i will only take a shot at deer 20 yds and under.
Having your own personal high level of personal confidence is a great place to be parked.
With well tuned shafts, sharp BH's and good shot placement, virtually all set-ups will work.
Do some adequate testing yourself to satisfy your curiousity.
Note: Typically there should be little if any discernable drop at 20 yards with a 75 gn increase at 20 yards with a 50# range bow if the arrow has been tuned properly.
We may be motivated for different reasons. My most recent motivation drove me to reduce my 400 gn - upfront 615 gn...32% Ultra-EFOC arrows...since I could not continually afford to replace targets. This set-up out of a 51# bow ate thru a Rhinehart BH target in less than a month, starting passing thru a new Eagle layer target in 3 weeks and has been quite abusive on my Morrell Outdoor range.
For me it wasn't a question of trajectory or penetration. It was about adding enough mass to a lightweight carbon shaft so my bow doesn't get beaten up shooting a light arrow plus the heavier arrow means the bow is quieter and has less vibration.
The rule of 10 grains per pound of draw means--for me about a 560 grain arrow. My shafts are 31" long at 9 grains ~300 grains. I need to add 260 grains to make weight. The only way to do that is with the broadhead/insert.
A whole list of opportunities may be made easily available by experimenting with shafts such as the Victory VForce HV, weighted inserts a selection of different field point weights. Then one can disern for themselves.
HV 400....6.9 gpi
HV 350....6.7 gpi
HV 300....6.9 gpi
Note: The more experienced you are with tuning will enable you to reap the possible benefits. It is possible to hit a road block and not realize that a golden opportunity is actually but a few steps away.