Ashby on light weight bows...

[bm22]

Dont you just love it when someone says they are testing penetration differences between arrow weights ans say they PROVE light arrows out penetrate heave ones when not one thing between the two arrows are the same. One arrow is carbon one aluminum, hmm which one penetrates better    one has a smaller diameter, which one will penetrate better?
Sometimes you just have to shake your head and go on.

About the size difference what is a 1/3  its all relative what is 10 lbs? If something weighs 1 lb and i add 10 thats a lot but if something weighs 10000 lbs and i add 10 not so big a difference. Now a 1/3 of an ounce is about 25% that can be a huge difference. If i added 50 lbs to a 200 lb. Man i bet he will know the difference.

You'll are correct about the diminishing return on an arrow, but 585 grain is no wear close to to heavy for that bow.

As far as accuracy goes whenever i lost an animal because of accuracy it was always a left or right shot, nothing to do with arrow weight. If you hit an animal low you probablyheart shot him if you dont do that you probably missed, i amfine with a miss. Plus how many people shoot self bows and claim them accurate. I can guarentee your glass bow with the heavy arrow willbe faster than 99% of the selfbows out there. Sure there will be a slight trajectory difference but nothing your mind wont easily adjust to.
With lower weights i like heavier arrows for more penetration go with the 585ish arrow, if you make a bad hit at least the arrow will cut as much as it can, complete penetration.

[Jason R. Wesbrock]

Call it boredom, but here's what I found on the internet pertaining to the ping-pong ball / golf ball analogy:

A ping-pong ball weighs 2.7 grams, or 41.7 grains.

A regulation golf ball can weigh no more than 1.62 ounces, or 707.7 grains.

Therefore, a regulation golf ball weighs 16.97 times the mass of a ping-pong ball.

Apply that ratio to the original poster's 480-grain arrow and we come up with a comparative arrow weighing 8,146 grains.

[SteveB]

Jason - gets even better when you go golf ball to bowling ball - 1.62 oz to 16 lbs.

And yes - I have seen this analogy used - much more then once.

Steve

[JimB]

It is worth reading the Ashby reports.Penetration is drastically affected by many aspects,shaft diameter,shaft diameter in relation to broadhead ferrule diameter,shaft surface finish-it goes on and on.Foam targets are poor predictors of how arrows will penetrate on game.

The only way you can truly compare to find out how weight affects penetration is to have the 2 arrows equal in every aspect except weight.Same point,same shaft material,diameter and finish.

[Rob DiStefano]

aaaaaaaaaa, enough of all this - just hone yer shooting accuracy to a consistent level, keep within yer consistent distance range, use a sharp broadhead.  

[Littlefeather]

Charlie, 40 grains can be a heck of a lot depending on what you are weighing.    

Jason, You are hands-down the go to guy for me when it gets to the details of any issue. Damn, where the heck did you get the weight of a ping-pong ball. LOL! That in itself was a something a lay awake thinking about at night, the exact weight of a ping-pong ball. Heeeheeeeeeee! I'm gonna go weight some crickets now.    

Dr Ed should arrive here at the house later this week. I'll notify him of this thread. He just loves it when everyone starts thinking about this stuff. I'm sure he'll get a chuckle reading some of this.

Here's a simple statement: I shoot a 48# bow most of the time. My arrows weigh between 600-630 each. Why? I shoot short yardages, I shoot hogs mainly and I always shoot for he shoulder bone, and I like the reduced vibration and reduction of noise when shooting heavy arrows. I get outstanding penetration on all game I shoot with this set-up. I'm still not sure I'd see any difference in 40 grains added or reduced in arrow weight. 40 grains just isn't much. Good luck. CK

[Littlefeather]

Sorry, I misread 140 grains as 40 grains. Dyslexia kicking in this morning.  :D   140 grains difference all in the front can change things quite a bit. CK

[elknut1]

Don't know guys, it's pretty tough to argue/debate with success! (grin)

  Just got done with round 2. The 485grn wins again! (grin) I put several shots into 5/16" Hardi Plank Cement board. I shot a 617grn 2018 aluminum & a 617grn beman 400 mfx & the beman 500 mfx 485grn all had 200grn up front. The 2 - 617 grain arrows hit hard & went through 2 sheets that were tight together at 20yards & hung up in the feathers after 3 straight shots each. The 485 grain arrow blew completely through both & exited into the bag target on all shots. The 617grn arrows never did.
  I then added 3 planks together & shot one shot each, the beman 617grn arrow & the 2018 - 617grn, both stuck aprox 1" into the planking & destroyed both front ends of each arrow. The 485grn arrow stuck out all 3 planks by 1" with not damage to the arrow.

  I'm not bias here & I don't sell arrows, these are my findings & all are welcome to have their own tests. But for me if I'm hunting hogs or elk the 485grn arrow will be in my quiver. I've proved to myself at the very least that it has superior penetration abilities over the slower heavier arrows. Dr. Ashby is more than welcome to come & exercise his opinions as well but nothing can negate the tests I've personally done!
   Sure hogs & elk can be killed with razored up heads on 375grn--700grn arrows that's not in question, what's in question is the ultimate in penetration & speed for a given bows draw weight. 48#-56# you're very well suited with 475grn to 515grn for awesome penetration!
  I will say this, a hogs armor plate is nothing in comparison to 1" Hardi Plank Cement board! Go shoot some yourself & you'll see what I mean, be ready to cough up the arrow because it will blow it up! Have a great day guys!!!

  ElkNut1

[Jason R. Wesbrock]

Originally posted by Littlefeather:
Damn, where the heck did you get the weight of a ping-pong ball. LOL!

Google.   :D

[TNstickn]

I imagine shaft diameter is playing a huge roll here as well. Heavy is good, skinny with adequate weight is better. JMHO >>>-----> Greg

[nightowl1]

alright fellas...didn't know this was gonna go own like this.... i shoot deer and hogs, in a few years elk(by then i will have the experience to make my decision on them).

to let everyone know i just purchased 24 gold tip blems from bigjim. great price great weight system and i should be at about 480gr when all is said in done...pice was just too right to pass up.

i know this setup will kill anything in texas and for now thats all i need.

btw i'm typing this with my 2 day old baby girl in hand...life is great!

[katman]

Interesting findings Elknut, your 8.6 gpp penetrates better than your 11 gpp arrow and is more durable. Scratching my head on that. I am not doubting what you saw but I wonder if all else was equal like arrow tune, angle of impact, broadhead type and sharpness.

Maybe each bow has there own best arrow weight? as no two bows, not even from the same maker are exactly the same. Also using such a rigid test medium maybe a single bevel would do better with the heavier arrows but there weight is below the bone threshold put forth by Dr Ashby. Pain in the wallet destroying arrows so I can not blame you for the limited data.

Your findings do go against common beliefs that heavier is better for penetration. I have not got a clue why the lighter was more durable. I hope Dr Ed chimes in and gives his opinion also.

[tawmio]

one well placed shot -even with a 40lbs bow will do. id prefer accuracy over an arror thats heave that i ca

[tawmio]

nt place propperly bc of its weight.
I shoot a 53lbs longbow with a 430gr arrow

[elknut1]

Katman, LOL!! Thanks for the humor there! It's good to see you & others can see that I'm not trying to tell anyone what they should do, I'm merely doing some testing & sharing the results. The thread starter asked which arrow was best suited for his 48# bow setup, 485grn or 615grn arrow? I knew 615grn from previous dinking around type testing was too much for his peak performance! Yes it will kill, but he could get more out of his bow by dropping the weight to closer to the 485grn arrow.

  I'm finding in the hunting world that diameter & material play a very insignificant role. In the tests done with the 2 different materials it shows one does not out penetrate the other to the point of embarrassing the other, they are generally within 1/4". ----We're not building a piano here! (grin)

  I also tested the 3 shafts with identical head weight of 200grns by shooting them into a newer 3d hog I bought from the 3d shoots, it's tough material for sure, it takes 2 hands to remove arrows. Both the MFX beman & the 2018 aluminum in 617grns went in 5" to 5 3/8" they traded those depths equally, no significant difference at all. This was measured penetration not how much arrow was sticking out. There were no other holes to accidentally hit on this target. After those I then shot several more times into the hog with the 485grn beman mfx with 200grn head wt. & received 6 1/2"--7" of penetration on each shot all from 20yds. The 485grn arrow bested them again!
     This was done prior to the Hardi Plank shooting. All 3 arrows are flying excellent, (well they were-grin) no issues to hinder penetration. Funny thing is even if some were wobbling the best they may do is catch up to the 485grn arrow! Maybe the 485grn one could be spined better & penetrate deeper? I'm throwing all this out there because of somes response! (grin) Some are so ingrained in what they want to hear & not except the results, why? If your bow falls into the 48#-56# range go out & shoot a 615grn or 700grn it doesn't matter & test the value of its penetration against a 475grn--515grn arrow & you too will shake your head as I do!
  Enjoy your weekend folks!

  ElkNut1

[J-dog]

My main target are 115 lb WTs! I shooot axis arrows, with either a 260 something grain grizzly or a 225 grain woodsman on the front. Been workin for awhile, will stick with it. Sorry have no clue what the arras weigh???

The Dr.'s research I think is some of the most interesting reading there is and I cannot wait for him to do some more. I am going to try some AD hammerheads this year due to his research. but use the same heads. I gotta figure he has shot probably 5 times more animals with the bow then I could dream about shooting!!! WHO am I to disagree.

And yes I can think back and probably blame 2 lost deer to lack of penetration. but that was an older setup I used to use - but these two deer are the reason I have been paying attention to the Docs stuff and thinking what I can try.

This has been an interesting thread with good points by all.

J

[Jason Jelinek]

elknut1, what was the specs on the 485 grain arrow and 615 grain arrow, it sounds like they are both beman mfx with 200 grain points.  If they are both flying well, they must be different lengths or of different spine.

[elknut1]

Jason, yes Sir you are exactly correct! I weighed each arrow until weights were acheived. The 485grn arrow is a Beman MFX .500 spine 27 1/4" 3-5" feathers. The 617grn Beman MFX .400 spine 27 1/4". The 2018 aluminum is 27 1/2" with a 2 1/4" 2216 collar added for wt. & strength 617grn. Both 617grn arrows have 200grn field-tips. The 485 grn arrow has a 75grn brass insert & a 125grn field-tip.

  I'm considering building a 425grn arrow & a 675grn arrow to see if they pull further away from the penetration the 485grn arrow is getting? I think they will according to everything else that has showed. Peak performance appears to be in the 475grn--515grn for the 55# drawn. As arrows lighten up or weights are added the performance suffers in both directions showing me that too light or too heavy is being obtained.

  For deer sized critters it's not that important, anything blows through a deer. No offense now, it's just that arrows melt through them when compared to hunting & killing elk. In elk hunting a hunter needs to be as close to peak penetration/performance as is reasonably possible for ultimate penetration & speed especially so in bows in the 45#--55# range with 3-bladed heads.
  You never know when that 30yd-35yd shot will present itself, I want to know I'm sending everything my bow has to offer at him at that time! If I do my part I want my setup to do its part, this is no time for disappointments!
   I know weight=momentum but there's a peak performance in each bow, shy of that or too much & you go the other way, if you go too much you can really suffer & have penetration issues.

  By the way, the 2018 bent just past the 2 1/4"collar on the Hardi Plank making it unusable for future testing. The MFX .400 tip looked great but part of the insert broke & shoved a few inches up the shaft & is coming out the side, it definitely blew up. (grin)
   Even if all 3 weights tested were equal in testing I'd go with the 485grn arrow because of the trade-off in trajectory. At 35 yards the difference is close to 24" in drop, Wow!!! But it doesn't suffer, it actually is still the better performer!

  ElkNut1

[James Wrenn]

Elknut I have to agree with you 100% on what you are saying.It is easy to get caught up in the heavy is always best thing and that momentum is the only thing that works.But the truth is the speeed that so many play down is a big part of the equation as well although many want to turn there back on it. Thanks for your impute and results.  

[IronCreekArcher]

Gentlemen,

Read the good Doctors results and scientific approach to testing broadhead penetration and arrow weight.  Variables pertaining to arrow composition/design and weight have been tested and measured/quanified.  It really is pretty simple in reagards to arrow weight alone and not factoring broadhead design or arrow diameter etc...physics dictates as follows:

Force = Mass x Acceleration

That means there is a balance between speed and mass.  You can not have all one or the other and expect the same penetration result.  An extreme example might be as follows:  Take an 800 grain arrow and shoot it out of a 20 lb bow...penetration will be minimal as the bow does not have the energy potential to increase the acceleration of the arrow.  Now take an 80 lb bow and shoot a 200 grain arrow out of it...penetration will still lack because the mass thats needed for adequate penetration does not exist.  Run the numbers in the formula above and have fun with the arrow weight combinations...you will eventually find the point of diminishing returns for your individual set-up.  As a side note...razor sharp single bevel broadheads would greatly help with penetration gains as well.  The Ashby reports are posted on this site for a reason...check them out the facts are undisputable.