Bullet Effect

[markT]

Just got back from prairie dog hunting in WY.. had some pretty good days.
I had a buddy out and he was shooting a 223 and a 6 BR..
The question arose as to why an animal gets hit with a (Vmax in this case) let's say dead center in the chest and does a "stage left" exit? Or, flies straight up off the mound.
Can someone explain this? Thanks..

 

[snert]

All depends on his disposition...

Or which way his liquified guts headed when that bullet hit. If out his butt, then expect a missile. If out a torn abdomen on right, expect a left scoot. Does it really matter?

Then again maybe it has to do with perspective...maybe they go the direction their little brain was intending to go just before the event.

 

[Gary in MD]

Ahhhh, one of the world's more intriguing questions! One that I have contemplated many times over the years looking for that special blend of accuracy and carnage . IME, it varies from varmint to varmint. Sometimes we will hit a 6 - 8 pound ground hog and he just dies rather uneventful and other times they will somersault 3 feet in the air - almost like they were spring loaded. Its the same with how busted up they get, sometimes they don't get too busted up and other times they just come apart. Of course it depends on what you hit them with, how fast it's going and the rpms of the bullet.
I've shot them with everything from a 22 rim fire to a 7mm STW and still nothing is chiseled in stone....
It's still kind of fun to really whomp a varmint hard!!
Gary

 

[5spd]

I don't have any reasoning for the way they may fly when hit at any range.
I have had them pop up into the air, fly right or left and just fall over at all odd ball ranges, but as long as I hear the twap it really don't matter to me in the end. We could all loose hair trying to figure that out.

 

[edw]

I have no idea either why the reaction happens. I do know that it happens a lot with a 204

 

[varmintshooter]

It may be that when a bullet impacts pressure builds in the body forcing stuff out of its butt which would then act as a propellant and that is what determines the direction of departure, or maybe not.

 

[fredo]

Straight up implies critter was on a hard 'launching pad' like a rock or other firm substrate. If its off to an angle, might could be the 'launching pad' was canted to favor stage exits?

Reckon if ya threw eggs into a right hand spinnin' fan, they'd splatter in random different directions. Same happenstance applies to a p-dog gettin' hit by a right hand twisted bullet spinnin' at a couple-3 hundred thousand RPM...

 

[dedogs]

spinnin' at a couple-3 hundred thousand RPM

fredo, Could you please explain this? To me a bullet fired down a 12 twist barrel rotates exactly 1 time in twelve inches which computes to 300 times @ 100 yds. Thanks, dedogs

 

[tn6br]

fredo, Could you please explain this? To me a bullet fired down a 12 twist barrel rotates exactly 1 time in twelve inches which computes to 300 times @ 100 yds. Thanks, dedogs

Rpm revolutions per minute, not rev per foot, 3,000 fps is 180,000 fpm in a 12 twist that would make 180,000 rpm 12 twist making 1 rev per foot

 

[lpreddick]

I don't have any reasoning for the way they may fly when hit at any range.
I have had them pop up into the air, fly right or left and just fall over at all odd ball ranges, but as long as I hear the twap it really don't matter to me in the end. We could all loose hair trying to figure that out.

I am a devout student of terminal Ballistics. I have hunted ghog for 15 yrs and seen many reactions to this effect. Our projectiles carry energy as per the formula E=1/2 MV(squared). At impact this energy creates pressure on and in the target. This pressure (shock) can liquefy organs (water rich) or break bones. If the projectile deviates from a straight line of flight( hitting bone or thick body parts) it takes this energy/shock/pressure with it and may exit the target. One on Newton's laws...for every action there is an equal and opposite reaction and is noted when projectile exits left taking blood and body parts and body exits right. This effect is noted if you shoot a grapefruit and noting parts of the fruit coming toward the shooter. Re an animals reaction to being shot... If the energy transfer is internal, a hydrostatic shock can shut down the nervous system so quickly that the animal drops instantly...no muscular reaction. If the nervous system doesn't shut down immediately, muscular contraction can have the animal launching with flip and flops. Small targets (pdogs,crows) cannot contain this energy so they literally explode. A large ghog might stretch/expand when shot keeping all the bullets energy internally and these animals usually die instantly.

 

[fredo]

fredo, Could you please explain this? To me a bullet fired down a 12 twist barrel rotates exactly 1 time in twelve inches which computes to 300 times @ 100 yds. Thanks, dedogs

Here's a good reference:
http://bulletin.accurateshooter.com/2008/06/calculating-bullet-rpm-spin-rates-and-stability/

 

[alinwa]

Just got back from prairie dog hunting in WY.. had some pretty good days.
I had a buddy out and he was shooting a 223 and a 6 BR..
The question arose as to why an animal gets hit with a (Vmax in this case) let's say dead center in the chest and does a "stage left" exit? Or, flies straight up off the mound.
Can someone explain this? Thanks..

As usual, my experience differs from others.....

I'm a firm devotee of the Suck Effect, ie you wanna see him fly, hit him high and SUCK him into the air.....if'n alls you see is head, SUCK him out of the hole with a headshot.

Hittin' 'em low just causes a scoot unless you intentionally MISS low and blow him into the air with dirt

And the greater the twist, the greater the splatter. I'll still argue that running 4000fps from an 8" twist will make the pieces spin out of the scope clockwise.........LOL

 

[dedogs]

Thanks, good article. dedogs

 

[Steve morgan]

fredo, Could you please explain this? To me a bullet fired down a 12 twist barrel rotates exactly 1 time in twelve inches which computes to 300 times @ 100 yds. Thanks, dedogs

No look up bullit rpm calculator