THE ACCURATERELOADING.COM BOW HUNTING FORUM


Moderators: Canuck
Go
New
Find
Notify
Tools
Reply
  
how is power measured?
 Login/Join
 
One of Us
posted
when a bow has xx lb draw weight, is this a measure of its power?

how much power is needed for hunting black bears?

in the trophy pics i have seen most hunters use compounds, are these the most practical?
 
Posts: 930 | Location: Norway | Registered: 31 March 2007Reply With Quote
One of Us
posted Hide Post
Steffen,

Below are some links to help you. the first lets you calculate your kinetic energy and the second gives you a range of what you will need to harvest different animals. The following text was copied from.

http://www.huntersfriend.com/b...htm#16-kineticenergy

Kinetic Energy: Arrow Mass & Arrow Velocity

So how does energy storage and arrow speed translate into actual hunting penetration? In the shooting sports, penetration is most often expressed as a function of kinetic energy (KE). This topic is covered in great detail in our Arrow Selection Guide, but we'll mention the highlights here in the bow guide as our final thought on bow "power".

In the end, the measurable "power" of your new bow - it's total kinetic energy output - ultimately depends upon just two variables: the mass of the arrow and the speed of the arrow. Kinetic energy of an arrow can be found by using the formula KE=(mv²)/450,240 where m is the mass of the arrow in grains and v is the velocity of the arrow in fps. So if your new bow setup ultimately shoots a 400 grain arrow at a respectable 250 fps (a typical field-output for a modern rig), your actual kinetic energy or "power" will be:
KE=(mv²)/450240
KE=[(400)(250²)]/450240
KE=25000000/450240
KE=55.53 ft-lbs

So, will that be enough? Take a look at Easton's Kinetic Energy Recommendation Chart.

Kinetic Energy


Hunting Usage

25 ft. lbs.
Small Game (rabbit, groundhog, etc.)

25-41 ft. lbs.
Medium Game (deer, antelope, etc.)

42-65 ft. lbs.
Large Game (elk, black bear, wild boar, etc.)

> 65 ft. lbs.
Toughest Game (cape buffalo, grizzly, musk ox, etc.)

According to Easton's recommendations, 55 ft-lbs of KE would be plenty for most popular North American game species. But is that a guarantee of success? Absolutely not!

Remember, bowhunting is a traditional and difficult sport. And regardless of how you crunch your numbers during pre-season, you can't avoid the elements of chance during the actual hunt. Shooting a live animal in the woods is quite different than shooting a block of ballistics gel in a laboratory. In the field you'll encounter unpredictable and complex variables that limit any mathematical model to just a "best guess". If you consider that your arrow must arrive on target then pass through layers of hair, hide, muscles, bones (perhaps), and a host of other tissues.....AND that all of this is happening in an uncontrolled outdoor environment, it's pretty clear that the issue of hunting penetration cannot truly be distilled into a mathematical puzzle.

As many experienced bowhunters can attest, just as it's possible to make mistakes and get lucky, it's also possible to do everything right and come-up empty handed. That's just part of the sport. However, with good equipment, good technique, smart planning, and some common sense, you can surely tip the scales in your favor and maximize your chances of success in the field.

http://www.bowhuntinginfo.com/KineticEnergyNew.htm


"I can't be over gunned because the animal can't be over dead"-Elmer Keith
 
Posts: 551 | Location: Northwestern Wisconsin | Registered: 09 April 2007Reply With Quote
One of Us
posted Hide Post
a .458 WM won't guarantee you success, but a .308 Win will do the trick if you do your part.

that said, this morning i didn't know anything about bows.

i think it looks interesting and i've searched on the internet to learn more about it.
bows can kill fairly large animals and there is no limitations when buying one, meaning it won't take up any space for other hunting firearms.
that alone is reason to get one.

and if i do get good at it and get bitten by the bug, black bear hunting in NA would be on top of my list.
so when i get one, i'll go for a bow that would perform well on the above application.



so...assuming the hunter does his part and uses suitable arrows:
55lb is enough?
 
Posts: 930 | Location: Norway | Registered: 31 March 2007Reply With Quote
One of Us
posted Hide Post
55 pounds will get the job done assuming the broadhead gets put in the right place. I was in the tree beside a friend one evening when he shot a black bear with a 45lb recurve and got the arrow buried all the way to the fletching. The bear ran 30 yards and collapsed. He dressed 312lbs.


"I can't be over gunned because the animal can't be over dead"-Elmer Keith
 
Posts: 551 | Location: Northwestern Wisconsin | Registered: 09 April 2007Reply With Quote
One of Us
posted Hide Post
Steffen,
If you want to see how a bow is "set up" go to www.bowhunting.net and click on the "BowTube" videos "Turkey Bow Set-up" and "Sighting in".
The basics are covered, if you don't have a pro shop nearby.
 
Posts: 227 | Location: Calgary, Canada | Registered: 06 March 2009Reply With Quote
One of Us
posted Hide Post
It depends on the regulations in the state you are hunting bear or deer. In the state of Wi where I hunt bear. The regulations are you must use a compound/recurve/long bow having a draw weight of 30# minimum or a crossbow of 100# minimum to legally hunt bear. So if you shoot a compound bow it must be 30 pounds or more to hunt bear and or deer in this state. I might add that bears are actually "softer" than a deer and if you hit them in the "kill zone" they expire rather quickly and easily. So, yes, in effect the draw weight of the bow is the determining factor as to, "does it have enough power to be effective to legally kill bear and deer". Now if you want to know how much “power your bow” is capable of, then that is called the stored energy of the bow and if you want to know how much “power your arrow” has in flight, that is called kinetic energy. These have to be measure on your bow/arrow system. But they are not used to determine if they are legally acceptable to hunt with. The draw weight is!
 
Posts: 157 | Location: Kenosha, WI | Registered: 25 February 2005Reply With Quote
  Powered by Social Strata  
 


Copyright December 1997-2023 Accuratereloading.com


Visit our on-line store for AR Memorabilia