Author Topic: blunts- kinetic energy or momentum  (Read 1648 times)

0 Members and 1 Guest are viewing this topic.

Offline Newindian

  • Member
  • Posts: 734
blunts- kinetic energy or momentum
« on: October 02, 2015, 05:51:45 pm »
in the primitive world we should usually chose momentum over kinetic energy in our arrow set up, but when we are shooting blunts and there is no notable penetration should we make our arrows favor speed/kinetic energy in stead of momentum?   
I like free stuff.

Offline Dakota Kid

  • Member
  • Posts: 897
  • Maker of Things
Re: blunts- kinetic energy or momentum
« Reply #1 on: October 02, 2015, 06:50:17 pm »
Your looking to transfer the force of the arrow into imact trauma. Force=(mass x acceleration). A nice heavy blunt tip moving at a good clip is what you're after. The same force normally used for penetration is transferred to impact shock due to the tip design. If you take the weight of the projectile down too much you'll never achieve the speed necessary to generate a terminal impact.

Going with a slightly faster set up might be preferable depending on the targeted critter.You don't need a whole lot of impact trauma to kill rodents(including tree&yard rats :laugh:) or birds. Most small game species move quickly and constantly. A slower arrow might not get there before the little bugger darts off again.  If you're shooting coons, weasels, possums, or any other tough creature go for the harder hit or use a broad head.
I have nothing but scorn for all weird ideas other than my own.
~Terrance McKenna

Offline Buck67

  • Member
  • Posts: 192
Re: blunts- kinetic energy or momentum
« Reply #2 on: October 02, 2015, 07:13:54 pm »
I made some blunts of Hickory with just a plain round tip.  Nothing fancy, no bulged wood or anything.  Shot it into my target.  The arrow penetrated 6".  We were on a 3D woodswalk and got tired of breaking arrows.  We took broken arrows, sharpened them with a knife and they stuck in the targets as well as the ones with points.  The nice thing was that they bounced off from trees with just a little blunting of the sharpened point.

So don't think that you won't get penetration with a blunt.  6 inch penetration with a blunt is true "blunt force trauma".


Offline Dakota Kid

  • Member
  • Posts: 897
  • Maker of Things
Re: blunts- kinetic energy or momentum
« Reply #3 on: October 02, 2015, 07:22:42 pm »
A true "blunt" point compacts and crushes the target/tissue rather than penetrates. A sharpened point cuts into and pushes material to the side to "penetrate", actually doing little tissue damage aside from the laceration.

A blunt point can bury itself into an animal there's no arguing that, but it's the difference between a 10 point dive and a belly flop.
I have nothing but scorn for all weird ideas other than my own.
~Terrance McKenna

Offline bowandarrow473

  • Member
  • Posts: 696
Re: blunts- kinetic energy or momentum
« Reply #4 on: October 02, 2015, 09:11:17 pm »
As with anything, I think there is a happy medium that yields great speed and momentum, shooting a Ping pong ball at a rabbit isn't going to do anything, nor is a telephone pole, there is a medium arrow weight that gives the best of both worlds. Think of it like this, if the arrow is to light it has no momentum, to heavy and it still has no momentum. There is a place where the speed and momentum are at a maximum and therefore so is the trauma inflicted. This is probably around 9-11 grains per pound if I had to guess.
Whatever you are, be a good one.

Offline Pat B

  • Administrator
  • Member
  • Posts: 37,496
Re: blunts- kinetic energy or momentum
« Reply #5 on: October 02, 2015, 11:06:27 pm »
I try to shoot the same arrows(size and weight) for everything, hunting, target, 3D, et al. It helps to keep my shooting consistent. I like a little penetration with the blunt force trauma for small game. The best small game point is such a simple idea. A 3/8" hex nut screwed on the tapered end of the arrow with a drop of super glue for insurance. I've hit squirrels with blunts and even Judo points and had them run off. Hit a squirrel with a "nutter" and he's DOA.  ;) Using hardwood shoots and some cane works well because they are naturally weight forward anyway.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

riverrat

  • Guest
Re: blunts- kinetic energy or momentum
« Reply #6 on: October 05, 2015, 10:49:55 pm »
i try to make wide blunted ends on a few of my arrows so they are close to same weight and ballance as my pointed arrows. dont have to break flint or glass points hitting rocks or something that way practiceing.but they are still great to practice with.in the past ive used blunts that looked kind of like mini baseball bats with feathers. killed a few squirrels with them.sent a few to Aquerogringo and he got a jack rabbit with one in Arizona. yep killed it. had pictures to prove it. i dont think hes at the sight anymore. i looked through the archives and members but couldnt find him or anything he ever posted. anyways, as i remember them, mine flew slower than my pointed arrows. they were a lot heavier.nose heavy.if they hit a tree, bark flew off. there was a 4 legged critter at a park next to my old house once, came at me with barred fangs, drool, fur standing tall on its back.running fast as its furry feet would carry it right at me. i had been practicing with the set of arrows i made for myself which included a few blunt arrows.i aimed for its nose, no luck, head shot, yelp, knocked it out cold! after a few minutes it woke up and staggered away. it didnt seem in such a bad mood anymore. probley had a pounding headache.thinking on it, i need to split out some hickory....Tony