Arrow weight for elk?

[svivian]

I shoot a 470 gr arrow at 295 fps.... Find a nice balance of speed and weight.

 

[PathFinder]

KE does not necessarily = penetration. Momentum = penetration. Momentum is a vector value, meaning that it has direction (ie in the direction the arrow is moving). KE is a scalar value, and has no direction. It's a great indicator of killing ability for rifles (ability to displace tissue in different directions) but that isn't how arrows kill. They cut along a straight path as the arrow penetrates. Arrow setups with more momentum penetrate more, and are more resistant to deflection. You'll have to do the math to find the point of diminishing returns in terms of trajectory and momentum. My new setup is 470 gr @ 285 fps.

 

[robtattoo]

I don't know whether any if you know about this, being a recent convert to wheel-bows from more traditional fare.
Dr. Ashby's reports have been a huge help in directing my traditional arrow building.
He did a series of penetration variables tests over many years & published the results......

http://www.alaskabowhunting.com/Dr.-Ed-Ashby-W26.aspx

 

[joshkaywood]

I don't know whether any if you know about this, being a recent convert to wheel-bows from more traditional fare.
Dr. Ashby's reports have been a huge help in directing my traditional arrow building.
He did a series of penetration variables tests over many years & published the results......

http://www.alaskabowhunting.com/Dr.-Ed-Ashby-W26.aspx

The link for momentum v KE doesn't seam to be active. I have been looking for some science driven data as I am currently wrestling with this debate for my first elk hunt. I feel like everything I have heard on both camps (light vs heavy) has been anecdotal for the most part. The physics of both seem to make sense, however I eventually get caught in some sort of logic loop after a while. I would love to see any reports people could present links to!

 

[ElkNut1]

For compound bows from 60# & up shoot arrows that fall between 6.5 to 7 grains per pound of draw weight, this is for total arrow weight which includes broadhead! For Trad gear aim for 8.5 to 10 grains per pound of draw weight. Example - 55# at 9 grains per pound = 495 grain arrow with broadhead. This is a very good measuring stick for ones bow of choice, this way you know you are not too light or too heavy thus maximizing speed & penetration!

ElkNut1

 

[slick trick]

so my 340gr arrow running at 315fps is a little light ??

 

[ben h]

Robtattoo, great link. The link to Dr. Ashby's actual paper was a little off but I still found it. Try this one and hope you have an hr to kill, it's pretty long.

http://www.alaskabowhunting.com/Ashby-On-Momentum-Kinetic-Energy-Arrow-Penetration-W19.aspx

Sure made me wish the US would switch to grams and meters to make reading this stuff easier.

Slick trick, I think 340 is really light; you'll be surprised adding 100 gr, you won't loose as much speed as you think.

 

[robtattoo]

The link for momentum v KE doesn't seam to be active. I have been looking for some science driven data as I am currently wrestling with this debate for my first elk hunt. I feel like everything I have heard on both camps (light vs heavy) has been anecdotal for the most part. The physics of both seem to make sense, however I eventually get caught in some sort of logic loop after a while. I would love to see any reports people could present links to!

Here y'go!

http://www.alaskabowhunting.com/Ashby-On-Momentum-Kinetic-Energy-Arrow-Penetration-W19.aspx

 

[robtattoo]

The link for momentum v KE doesn't seam to be active. I have been looking for some science driven data as I am currently wrestling with this debate for my first elk hunt. I feel like everything I have heard on both camps (light vs heavy) has been anecdotal for the most part. The physics of both seem to make sense, however I eventually get caught in some sort of logic loop after a while. I would love to see any reports people could present links to!

Ah. Ben beat me to it!

 

[timekiller13]

I shoot a Bowtech Tribute at 60lbs. My whitetail setup was an easton axis 400 with 100 grain head. Weight was 385 grains. I wanted heavier so I went with easton FMJ 400s with 100 grains up front. Increased my weight to 425 grains. I lost about 20fps but I am very satisfied with the way it shoots.

 

[joshkaywood]

Here y'go!

http://www.alaskabowhunting.com/Ashby-On-Momentum-Kinetic-Energy-Arrow-Penetration-W19.aspx

Thanks bro. Definitely a wealth of knowledge.

 

[ElkNut1]

Slick Trick, yes 340 grains of total arrow weight is a bit of a light weight elk setup. What draw weight are you pulling?

ElkNut1

 

[Bitter24]

Well glad this started some good convo!

So, from what Im reading basically I want to be somewhere around 385-425 total arrow for my rig.

Couple different ways of affecting weight. I can have my arrows cut longer, add brass inserts or similar, or add a heavier broadhead. Which all of those besides arrow length afftects FOC. Are you guys at all watching the FOC and noticed if a certain % seems to work best, of is it really not that important.

Also, yes I am re doing my set up and now that I have a elk tag that is my end game. Though I still want a setup that is accurate and can strecth some range just for fun in the yard. Im really thinking I will stick with gold tip arrows. Probably either velocity or kinetics from GT. lol, I wont even bring what kind of broadhead up since that is always a mess. Though I have shoot 100 grain heads for a while now, though may go back to 125's?

 

[ElkNut1]

Actually your best penetrator will be from 410 grains to 440 grains at your 63# draw weight. Anywhere in that ball park will suit you very well & it will be good elk medicine. 100 grain heads are just fine if that's what it takes to get into your ball park weight. I like a bit more FOC such as 150 grains minumum up front, this includes broadhead & insert although it's not a deal breaker if you're not setup that way, your total arrow weight is the key factor.

ElkNut1

 

[Bitter24]

Elknut, thanks for the comments. I got to re read over everything again. Though now its time to start working up a arrow.

 

[Bonedalien]

i pay attention to FOC. it is especially important for accuracy at long range.
it is suggested 10-15 percent FOC for hunting set ups,and 7-10 percent for target bows.
mine is at 12.

 

[squeekieslayer]

Well glad this started some good convo!

So, from what Im reading basically I want to be somewhere around 385-425 total arrow for my rig.

Couple different ways of affecting weight. I can have my arrows cut longer, add brass inserts or similar, or add a heavier broadhead. Which all of those besides arrow length afftects FOC. Are you guys at all watching the FOC and noticed if a certain % seems to work best, of is it really not that important.

Also, yes I am re doing my set up and now that I have a elk tag that is my end game. Though I still want a setup that is accurate and can strecth some range just for fun in the yard. Im really thinking I will stick with gold tip arrows. Probably either velocity or kinetics from GT. lol, I wont even bring what kind of broadhead up since that is always a mess. Though I have shoot 100 grain heads for a while now, though may go back to 125's?

I would shoot for about 425 to 450 with your set up. I would say that correct spine is most important, and way more important than the FOC. Yes, FOC is important... but i see guys adding so much weight up front to get ridiculous FOC and end up complaining about their braodheads hitting left or right... you guessed it, ignored spine, added weight to get some amazing FOC and now they have to start over.

Decide what grain broadhead you want to shoot, get an idea of how long you want your shaft (haha,) and play with an arrow calculator to figure out the right spine. Personally I thin most worry too much. I know i am shooting a 100 grain head at 29,5 inch shaft. I find a shaft that comes in the correct spine and will give me the weight i want... I have never had a set up that i couldnt get to shoot well to 80 plus with fixed heads.

PS: try the Black eagle rampages. great arrows, good cost, very durable.

Jo

 

[ElkNut1]

sqeekieslayer, thanks! I should have mentioned that proper arrow spine is necessary for his draw weight & length to accomplish his ideal arrow weight. He should be in the .400 to .340 spine depending on arrow length & draw length. Of course this is important to all folks who shoot a bow. Thanks again!

ElkNut1

 

[Flatgo]

Don't over think it match the spine of the arrow to the bow and shoot a good strong hunting arrow like the Easton axis and you'll be fine. In the end it's where you hit them. If you hit bone other than a rib the arrow won't penetrate. No amount of weight will help this. Honestly broad heads have more to do with penetration than weight as long as you're not on the extremely light side. Shoot a cut on contact like a stinger or steel force phat head and you'll be fine

 

[slick trick]

66
lbs