Arrow weight vs speed

by **MLayden** » 04 01, 2014 • [Post 1]

I've been reading up a bit lately on this topic...where momentum is better carried through a heavier arrow vs light arrow. I've always tried to get a good balance in KE and speed. Thinking in terms of better penetration (hoping for better pass throughs, and exit holes) I'm thinking up upping my arrow weight, knowing that I will lose some speed.

http://www.qdma.com/articles/momentum-b ... arrow-hits

This article, the person recommends 8 grains per poundage of your draw weight. I think this could be quite heavy but deserves some thought...

What are your guys' opinion on this? Do you use a heavier arrow?

by **ferris bugler** » 04 01, 2014 • [Post 2]

As someone who shoots traditional I like to have extra weight. With that said, I won't add so much extra weight that I can see a dramatic change in arrow flight. With wheel bows I would guess that you can add weight and still get a very similar flat trajectory so there wouldn't really be a noticeable change in arrow flight. WIth the extra weight I have a lot more confidence about breaking through ribs or a shoulder blade. The arrow I shoot is around 750 grains.

by **Toby** » 04 01, 2014 • [Post 3]

While I think heavier gives more momentum, I still like a little speed. I only shoot 60#'s@28" so my 425 grain arrow is going about 260-265 or so. I don't pull the weight or have the draw length to generate the numbers that guys with a 30" draw and pulling 70#'s do. That said, I believe that a straight flying arrow out of a well tuned bow trumps weight or speed, within reason. If I could shoot big numbers I would up my arrow weight, but feel very confident in my set up. Get your rig tuned, keep your arrow weight in the mid range, not too light and not too heavy, 6.5-8.5 gpp, and put a good broadhead in the vitals and you are good to go.

by **POk3s** » 04 01, 2014 • [Post 4]

First it was the speed craze now it's the KE craze. If you ask me the KE "craze" is a much more safe craze to be associated with but there are a lot of people going overboard with it. In my opinion you need a happy medium. If you always had time to range your target before shooting than maybe a really heavy arrow would fit but most of the time I get a range while the animal is moving and then make an educated guess from there when I finally get a shot. He took 10 more steps but he was quartered away so now I think he's at x yardage and let the arrow fly. With a really heavy arrow you better be exactly right on yardage!

Another not is the formula to Kenetic Energy contains mass and speed. There's a point where you slow your arrow down far enough to where you're losing so much speed that you're actually hurting your kinetic energy. I don't think you weren't thinking of upping your arrow weight by that much but a scroll through some other forums will show you how crazy guys are getting with heavy arrows. Their arrows are 300-400 grains heavier than mine and they're getting 2 more foot pounds of energy....is that worth it??? not to me it's not.

by **jmez** » 04 01, 2014 • [Post 5]

I use heavy arrows. Going to be at 498gr this year with my setup.

This argument comes up a lot on the various hunting sites and is never ending. There are laws of diminishing returns at both end of the spectrum with speed and weight. If you are interested in the subject Google Dr. Ashby and read his work on the subject. He has done extensive testing. People have been killing big game animals for eons with slow traditional equipment and really heavy arrows. Most of the time with a pass through.

The laws of physics still apply. All else being equal, a heavier arrow will out penetrate a lighter arrow. To a certain point, a heavy slow arrow will out penetrate a light fast arrow. Where the argument comes in is how far in the dirt do you want your arrow on the far side of the critter. If a light fast arrow will shoot right through and elk why bother with a slow heavy arrow. I have more trust in a heavier set up on a big boned tough animal like an elk or moose. On deer sized game I don't think it matters at all.

I don't worry about misjudged yardage. When I set up to call I range several trees or objects in front of me before doing anything else. Even an a moving animal, I would have to be pretty far off on distance judging to miss or cause a bad hit. Even with a 500gr arrow. I honestly don't remember the last time I shot at an animal where I didn't have much of any idea what the distance was. If I'm doing that then 15-20fps isn't going to make the difference.

by **Trophyhill** » 04 01, 2014 • [Post 6]

I've toyed with different weights and different brands. And weighed my options. A GT XT Hunter with a 100 gr RazorTrick weighing in at 390 gr's total arrow weight is what flies best out of my bow. Last season on a frontal shot at 30 yards my arrow disappeared inside the elk. I don't care what all the charts say, that is full penetration and a quick kill! I think too many get wrapped up in mathematic science when all you have to do is find the setup that works best for you! Conversely a friend shoots a 25 year old bow using telephone poles for arrows around 500 gr and 250 fps and kills them just as dead!

by **Backcountry** » 04 01, 2014 • [Post 7]

People put too much emphasis into KE. A light arrow and a heavy arrow can have the same KE while maintaining drastically different momentums.

KE shows energy exerted on impact while momentum shows store energy through a motion. (Penetration). Momentum always wins.

by **mongopino915** » 04 01, 2014 • [Post 8]

Backcountry wrote:People put too much emphasis into KE. A light arrow and a heavy arrow can have the same KE while maintaining drastically different momentums.

KE shows energy exerted on impact while momentum shows store energy through a motion. (Penetration). Momentum always wins.

Around 500 grains is a nice mix for me. Not too slow (around 280 fps) but not so light that the arrow would be deflected by the elk rib cage bone.

by **JJ Overkill** » 04 01, 2014 • [Post 9]

whys everyone shooting such light arrows?????

612gr arrow going 298fps :twisted:

hey david, why did my arrow weighting 484gr shoot so well out of your bow last yr? same bow, your a 1/2" shorter draw than me, same draw weight. and my arrow out of your bow went farther into your deer target than your 390gr arrow. im just sayin :mrgreen:

but in all seriousness build an arrow that weights around 400-450gr if you can get your speed above 260-270 your more than good to go for elk.

my son for example is shooting a 487gr arrow and hitting 263fps. his momentum comes in at .568 KE of 74.72.

by **jmez** » 04 01, 2014 • [Post 10]

Backcountry wrote:People put too much emphasis into KE. A light arrow and a heavy arrow can have the same KE while maintaining drastically different momentums.

KE shows energy exerted on impact while momentum shows store energy through a motion. (Penetration). Momentum always wins.

KE is a marketing tool. Velocity is squared in the equation so little jumps in speed give big jumps in your KE number. KE is a big number, momentum is a decimal. Guys would much rather say I shoot 86lbs of KE rather than I shoot .602 ft/lbs or momentum. Marketing works.

by **Toby** » 04 02, 2014 • [Post 11]

40 years ago guys were killing elk with compound bows and 550 grain arrows that probably didn't hit speeds of 200 fps. Before that, they we're killing them with recurves and longbows probably shooting 140-170 fps, so most modern day compounds have way more than enough. Tune your bow, shoot quality Broadheads, hit them when they live and you will have plenty.

by **Trophyhill** » 04 02, 2014 • [Post 12]

JJ Overkill wrote:whys everyone shooting such light arrows?????

612gr arrow going 298fps

hey david, why did my arrow weighting 484gr shoot so well out of your bow last yr? same bow, your a 1/2" shorter draw than me, same draw weight. and my arrow out of your bow went farther into your deer target than your 390gr arrow. im just sayin

but in all seriousness build an arrow that weights around 400-450gr if you can get your speed above 260-270 your more than good to go for elk.

my son for example is shooting a 487gr arrow and hitting 263fps. his momentum comes in at .568 KE of 74.72.

Bet my rotator cuff lasts longer than yours lol. 80lbs is just a little more than I care to draw

by **MLayden** » 04 02, 2014 • [Post 13]

Buddy found this article on the net...
http://soleadventure.com/2013/06/the-be ... -look-for/

Worth a read too.

by **slim9300** » 04 02, 2014 • [Post 14]

I feel like the ideal elk arrow is around 450-500 grains for most modern bows. I like to see speeds in the 290 fps range and for me that means a 456 grain arrow, but I have the luxury of shooting a 61# bow.

If I shot 70# I would jump up to a 500 grain arrow in a heartbeat.

by **TxTechChuck4** » 05 16, 2014 • [Post 15]

I'm shooting a 389 grain arrow with at 70# flying at 285 fpm. Based off that info I am slinging 70 ft.lb of KE and momentum of .49. I am shooting flat up to 30 yards, that being said is this enough to take down an elk or should I consider upsizing to a heavier arrow?