[Mach 10]

Is a 365 Gr. arrow at 260 fps too light for elk ?

Mach 10

 

[lwilt]

not if your a good shot

 

[TCR1]

more accurately, no it is not too light.

Being a good shot is essential for any arrow combination.

I'm shooting a GT XT Hunter 5575 shaft cut to 27" with standard nocks andinsert, 125gr. head, EZE Crest reflective wrap and 2" blazers. I'm shooting this set up at 62 pounds out of a Hoyt Ultramag with a 27.5" draw length and it will be plenty.

 

[rhenj]

You are ok, 54 ft/lbs of KE. I always like a little more momentum (ie 450-500 grains arrow weight) to gain some penetration incase you center-punch a rib.

 

[bowhuntrrl]

I think it's too light.KE is meaningless when it comes to penetration. Momentum is what counts. More momentum=more weight. This is an age old controversy, but momentum is backed up by physics. In 2005, I killed a 6x6 bull at 50 yards. My bow was at 54 lbs. The arrow was 410 grains. I had no problem with penetration. I was using a Slick Trick 100 gr with 1 1/8 cut. A lot of western states have a 400 gr minimum. You need to check the regs for the state you hunt in.

 

[natec63]

bowhuntrrl, I think you are misplaced about momentum and KE. You are correct about them being different but if you read the following, I think you'll change your mind here.

http://www.batesville.k12.in.us/physics/phynet/mechanics/Energy/KENOTMomentum.html

 

[3B43]

The 'truck vs meatball' choice makes NO SENSE! Why? The 'correct' question, on this stupid example, is this:

With a 3/4" plywood wall in front of it, which one, the truck or meatball would go FARTHER if it struck the wall? I think we all know the answer to that one.

PLEASE go pick up a high school physics book and read up on the real difference between KE and Momentum

 

[Archer-Andy]

Most recommend 50+ ft. lbs. of Kenetic Energy for large game such as Elk.
Your arrow weight of 365gr and speed of 260fps should give you 54.8 ft.lbs of KE. Find your mark and your good to go!

 

[natec63]

Haven't picked up a hs physics book in a while so maybe I am off base. That's entirely possible as I've been wrong before and I'm sure it'll happen again.

As for your example, the only reason the truck might penetrate more is because the meatball is most likely going to disintegrate. What if you change it to a golf ball? Which would penetrate your 3/4 in plywood wall further then?

 

[Chukarhntr1]

Last week I took a yearling cow with a 385 grain arrow at 230 fps. I had a complete pass through. Pulled the arrow out of the dirt on the other side and she only went 100 ft. I may have been just lucky, but I'll let you make the call.

 

[TCR1]

I guess I should have looked at this first, but the approximate weight (not actually weighed on a scale) of my hunting arrow is 410 gr.

I actually didn't think it was all that heavy, until you add it all up.:darkbeer:

 

[natec63]

Ok, just found a good definition of mumentum:

Momentum is a property that tells us how hard it is to change the way an object is moving.

Obviously that is hugely important when arrows meet a rib or shoulder blade and I know understand why it's important. At the same time, momentum = mass * velocity . So if you are shooting a lighter weight at a higer speed, you could get the same momentum, correct?

 

[TCR1]

The 'truck vs meatball' choice makes NO SENSE! Why? The 'correct' question, on this stupid example, is this:

With a 3/4" plywood wall in front of it, which one, the truck or meatball would go FARTHER if it struck the wall? I think we all know the answer to that one.

PLEASE go pick up a high school physics book and read up on the real difference between KE and Momentum

Taking the meatball and changing it into a golf ball as suggested, I believe the golf ball moving at a high rate of speed would penetrate a 1/4" piece of ply wood while leaving a nice hole. Assuming the truck hits a well supported piece of ply wood, it would either bowl it over or break it in half, or disintegrate it, depending on the speesd it hits at.

To be honest, I don't know which I would personally want to get hit by. a force exerted by a single point is much more powerful than one distriburted along a larger area (thus the metal plating on the edge of stairs to protect from high heeled shoes).

 

[TCR1]

Ok, just found a good definition of mumentum:

Momentum is a property that tells us how hard it is to change the way an object is moving.

Obviously that is hugely important when arrows meet a rib or shoulder blade and I know understand why it's important. At the same time, momentum = mass * velocity . So if you are shooting a lighter weight at a higer speed, you could get the same momentum, correct?

Sure, but then you get into an argument of efficiency. Which is easier, adding 25 grains to an arrow or adding 25fps to a bow?

Hypothetical examples:
300 grain arrow x 200 fps= 60,000 rating of momentum (what the heck would these units be (grain feet/second )
or a 325 grain arrow x 190 fps = 61,750 gr. ft./s)
or a 275 grain arrow moving at 210 fps = 57,750 gr. ft./s)

to get a momentum of 61,750, you would need your 275 gr. arrow to go 225 fps. gaining 15 fps is a lot harder than adding the neccesary weight to an arrow.

 

[craig1017]

One thing you have to be careful of is that you are legal in the state you plan on hunting in. Many of the western states have a 400gr minimum weight for hunting arrows regardless of whether you *think* it is heavy enough.

 

[TCR1]

Lets top speaking in generalities then as far as regulations.

I know Colorado does not have minimum arrow weight
I know Idaho does have a 400 grain minimum arrow weight.

If you are elk hunting in Colorado, you are fine, if you are in Idaho, add weight. Can't speak to any other elk states.

 

[Maybee-R]

washington 300 gr. min.

 

[natec63]

TDR1; thanks for your explinations, I see the light.

3B43: instead of telling me the example was stupid and to pick up a HS physics post, try explaining why I was wrong. This forum is about helping, ya know?

 

[TCR1]

Not a problem. I moved out west about 6 years ago. Only animal I have harvested so far is a pronghorn. These things all work in the theoretical realm, its when you are on the ground that things get more complex. One thing I have noticed is that Elk probably won't jump a string like a whitetail. However, if they tense up, there is a lot of meat to get through. There is also something different about being that close to an animal of that magnitude as compared to a whitetail. I hopefully have my nerves under control this year, but we'll see.

Good luck on your upcoming hunt.

 

[Mizzoukispot]

You should really use the heaviest arrow that you feel that you can shoot well out of your set up.