Bullet penetration question: slow vs fast A Frame of the same grain weight
12-02-2018, 08:59 AM
#1
Spike
Thread Starter
Join Date: Dec 2018
Posts: 2
Bullet penetration question: slow vs fast A Frame of the same grain weight
Hey, question about bullet penetration performance. Here is the info:
Two swift A Frame bullets of the same weight, fired from the same rifle, hitting two bears of the same size and build, both at 100 yards and encountering the same trajectory masses through both bears...essentially all the same aspects except for velocity: one bullet hitting the bear at 2000 fps and the other hitting it at 3000 fps. Which one of these A Frames would have a deeper penetration?
For those questioning other factors, take for granted that all factors are the same except for velocity upon impact.
Thank you for your input.
joe.grey
Two swift A Frame bullets of the same weight, fired from the same rifle, hitting two bears of the same size and build, both at 100 yards and encountering the same trajectory masses through both bears...essentially all the same aspects except for velocity: one bullet hitting the bear at 2000 fps and the other hitting it at 3000 fps. Which one of these A Frames would have a deeper penetration?
For those questioning other factors, take for granted that all factors are the same except for velocity upon impact.
Thank you for your input.
joe.grey
12-02-2018, 11:40 AM
#2
Super Moderator
Join Date: Dec 2017
Location: texas
Posts: 1,201
generally higher velocity results in faster expansion,
more expansion results in a larger cross sectional area,
a larger cross sectional area results in more resistance too penetration,
this is partly off set by the higher impact velocity and energy,
keep in mind bullet construction and where on the anatomy the bullet strikes and how much bone it must penetrate, effects results
the higher the sectional density and the thicker the jacket the deeper the penetration tends to be.
if you value deep penetration select a bullet with a thicker jacket designed to slow expansion,
your 2000 fps bullets likely to punch deeper than the 3000 fps bullet impact
select the heaviest bullet with the thickest jacket, your rifle shoots accurately to insure deep penetration
with a .250-.300 sectional density , push it as fast as you can, safely
and select a decent name brand bullet,
your other option, select a reasonably heavy hard cast bullet in the .375 caliber to .500, caliber in that .250-.300 sectional density , and push it to 1800 fps-2100 fps
https://www.beartoothbullets.com/res...hp/density.htm
use a hard cast bullet of 400-480 grain weight in a 458 caliber like a 450 marlin,45/70 or down loaded 458 win
pushed to 1800 fps-1900 fps and you need not worry about a lack of penetration.
Id to be fair should point out that its a knowledge of the games anatomy and shot placement thats critical, and you don,t always need exit wounds to provide lethal damage, rapid expansion and deep penetration are both valuable traits, it only takes about 12"-18" of penetration in the correct spot to prove rapidly lethal, but an exit wound will tend to increase chances of a blood trail.
https://www.midwayusa.com/product/47...nose-gas-check
http://www.neihandtools.com/catalog/index.html
http://www.rifleshootermag.com/edito...s-market/83865
you might find these worth reading
http://thebiggamehuntingblog.com/hunting-cape-buffalo-with-the-45-70-government/
http://www.ballistics101.com/images/bear_images/bearshotplacement.pdf
more expansion results in a larger cross sectional area,
a larger cross sectional area results in more resistance too penetration,
this is partly off set by the higher impact velocity and energy,
keep in mind bullet construction and where on the anatomy the bullet strikes and how much bone it must penetrate, effects results
the higher the sectional density and the thicker the jacket the deeper the penetration tends to be.
if you value deep penetration select a bullet with a thicker jacket designed to slow expansion,
your 2000 fps bullets likely to punch deeper than the 3000 fps bullet impact
select the heaviest bullet with the thickest jacket, your rifle shoots accurately to insure deep penetration
with a .250-.300 sectional density , push it as fast as you can, safely
and select a decent name brand bullet,
your other option, select a reasonably heavy hard cast bullet in the .375 caliber to .500, caliber in that .250-.300 sectional density , and push it to 1800 fps-2100 fps
https://www.beartoothbullets.com/res...hp/density.htm
use a hard cast bullet of 400-480 grain weight in a 458 caliber like a 450 marlin,45/70 or down loaded 458 win
pushed to 1800 fps-1900 fps and you need not worry about a lack of penetration.
Id to be fair should point out that its a knowledge of the games anatomy and shot placement thats critical, and you don,t always need exit wounds to provide lethal damage, rapid expansion and deep penetration are both valuable traits, it only takes about 12"-18" of penetration in the correct spot to prove rapidly lethal, but an exit wound will tend to increase chances of a blood trail.
https://www.midwayusa.com/product/47...nose-gas-check
http://www.neihandtools.com/catalog/index.html
http://www.rifleshootermag.com/edito...s-market/83865
you might find these worth reading
http://thebiggamehuntingblog.com/hunting-cape-buffalo-with-the-45-70-government/
http://www.ballistics101.com/images/bear_images/bearshotplacement.pdf
Last edited by hardcastonly; 12-02-2018 at 01:19 PM.
12-08-2018, 02:35 PM
#4
Super Moderator
Join Date: Dec 2017
Location: texas
Posts: 1,201
if you were to study this chart of tested bullets and cartridges,(below)
it should be rather obvious that the higher sectional density (heavy for bore diameter projectile designs)
and more heavily constructed bullets, tend too penetrate significantly better and more consistently,
if you look carefully the best results tend too be projectiles that are not designed to expand rapidly.
full metal jacket bullets like many cartridges used for hunting elephant have exceptional performance,
but too many people its surprising that heavy hard cast revolver bullets or moderate velocity rifle bullets
can also provide exceptional results.
if youve hunted very long youll likely remember finding a few rifle bullets under the far side hide
remember many rifles have double the velocity and energy , or more of a revolver
thats not all that common with heavy hard cast bullets shot from a long barrel revolver,
you generally hear those exiting bullets, punching brush on the far side of game after its shot.
Ive used a 310 grain lee hard cast gas check bullet in my 44 mag pushed to about 1350 fps
and a 330 grain hard cast gas check bullet in my 445 dwsm pushed to about a similar velocity
both revolvers have 10" barrels, Ive yet to recover a bullet, they exit.
it should be rather obvious that the higher sectional density (heavy for bore diameter projectile designs)
and more heavily constructed bullets, tend too penetrate significantly better and more consistently,
if you look carefully the best results tend too be projectiles that are not designed to expand rapidly.
full metal jacket bullets like many cartridges used for hunting elephant have exceptional performance,
but too many people its surprising that heavy hard cast revolver bullets or moderate velocity rifle bullets
can also provide exceptional results.
if youve hunted very long youll likely remember finding a few rifle bullets under the far side hide
remember many rifles have double the velocity and energy , or more of a revolver
thats not all that common with heavy hard cast bullets shot from a long barrel revolver,
you generally hear those exiting bullets, punching brush on the far side of game after its shot.
Ive used a 310 grain lee hard cast gas check bullet in my 44 mag pushed to about 1350 fps
and a 330 grain hard cast gas check bullet in my 445 dwsm pushed to about a similar velocity
both revolvers have 10" barrels, Ive yet to recover a bullet, they exit.
Last edited by hardcastonly; 12-08-2018 at 02:40 PM.
