2600 fps "cut off point" for DRT behaviour?

CBH Australia

AH elite
Joined
Feb 10, 2019
Messages
1,629
Reaction score
2,046
Location
NSW Australia
Media
16
Hunting reports
Africa
1
Member of
Sporting Shooters Association Australia, Africa Hunting website!!!
Hunted
Australia and now South Africa
I formed the Opinion that Nathan Foster has a loyal following, I almost used the term cult following.
I take from it the bits I believe and can’t attest to from my experiences.

He is knowledgeable but we cannot replicate field shots to prove or disprove anyone persons theory. His interests are building his business on his reputation he is not a contributing writer but this website and his publishing are his bread and butter. That is good for him he built this for himself but I don’t hang on every word he says either.

Read enough to support the view you have formed or take the general consensus I find people are advocating a particular projectile for particular game. These might be lessons learned from experience. Equally if enough people are suggesting a projectile is not fit for purpose then maybe look at the alternative.

Trial and error are the best teachers, don’t intentionally wound game to drop it aim a little higher. For your own self esteem. Aim for accurate hunting rounds , hunt closer don’t shoot further. When I mess up a shot I question why? What did I do wrong when I took the shot? Usually there is an answer.
I did have a Hornady Zmax 168 grain break up on a pigs shoulder once. No scientific research but an importantly observation easily identified. Those projectiles will only be loaded for target practice not pigs, perhaps I would shoot a fox or thin skinned game if the shot presented with the given rifle and ammo.

There are many, many hunters here with more experience than me but I try my best and I took 10 cull animals with A hire rifle in SA all one shot kills.
My PH was pretty happy with that and well so was i.
 

Aaron Nietfeld

AH fanatic
Joined
Nov 18, 2014
Messages
660
Reaction score
713
Location
Alberta, Canada
Media
7
Articles
2
Hunting reports
Africa
2
Hunted
Canada, South Africa
Please be kind and forgive the ignorant.....

I honestly know nothing about hydrostatic shock, but why is it velocity dependant, and not energy dependant?
 

One Day...

Gold supporter
AH elite
Joined
Jan 7, 2018
Messages
1,229
Reaction score
3,156
Website
www.huntershillsafaris.co.za
Media
378
Articles
1
Hunting reports
Africa
3
Member of
PHASA
Hunted
Europe, America, Canada, Africa
You are correct, Aaron, hydrodynamic shock (not hydrostatic ;) - see my above first post, although I recognize that the technically wrong designation of "hydrostatic" is the common way to describe the phenomenon, even if there is nothing static about it :ROFLMAO: ) is of course energy dependent :)

But since kinetic energy is itself highly dependent on speed, because velocity (i.e. speed) is squared in the formula while mass (i.e. weight) is not, it follows that the critical factor in hydrodynamic shock is speed :giggle:

1605933981329.png
 
Last edited:

Aaron Nietfeld

AH fanatic
Joined
Nov 18, 2014
Messages
660
Reaction score
713
Location
Alberta, Canada
Media
7
Articles
2
Hunting reports
Africa
2
Hunted
Canada, South Africa
You are correct, Aaron, hydrodynamic shock (not hydrostatic ;) - see my above first post, although I recognize that the technically wrong designation of "hydrostatic" is the common way to describe the phenomenon, even if there is nothing static about it :ROFLMAO: ) is of course energy dependent :)

But since kinetic energy is itself highly dependent on speed, because velocity (i.e. speed) is squared in the formula while mass (i.e. weight) is not, it follows that the critical factor in hydrodynamic shock is speed :giggle:

View attachment 376423
Thanks for the physics refresher!
 

One Day...

Gold supporter
AH elite
Joined
Jan 7, 2018
Messages
1,229
Reaction score
3,156
Website
www.huntershillsafaris.co.za
Media
378
Articles
1
Hunting reports
Africa
3
Member of
PHASA
Hunted
Europe, America, Canada, Africa
In fact, there is substantial US military research that demonstrates the reality of the hydrodynamic shock. One of the most recent is this 2007 paper:

1605936140341.png


Page 2 states:

1605936183801.png


Please note that most US military studies involved the 5.56x45, 5.45x39 and 7.62x39 rounds and that these rounds are much slower than high velocity hunting rounds such as the .257 Wby, 26 Nosler, etc. The 5.56x45 typically drops below 2600 fps at 150 yards, the 5.45x39 at 75 yards, and the 7.62x39 barely reaches 2400 fps at the muzzle.
  • Whether the hydrodynamic shock destroys the animal brain or simply knocks the animal unconscious to die from the massive thoracic respiratory and circulatory wound in the following few minutes is unknown to me;
  • What exact impact energy/speed is required to produce a 30 PSI pressure wave in which animal size is also unknown to me;
  • What I know, is that based on my admittedly limited .257 Wby experience, it seems that impact velocity above 2700 fps (or maybe 2600?) with a bullet at least 100 gr in weight, with a double lungs shot in PG - up to 500 lbs. in my personal experience, but maybe more? - does trigger instant incapacitation.
Just my $0.02...
 
Last edited:

CBH Australia

AH elite
Joined
Feb 10, 2019
Messages
1,629
Reaction score
2,046
Location
NSW Australia
Media
16
Hunting reports
Africa
1
Member of
Sporting Shooters Association Australia, Africa Hunting website!!!
Hunted
Australia and now South Africa
Please be kind and forgive the ignorant.....

I honestly know nothing about hydrostatic shock, but why is it velocity dependant, and not energy dependant?
Nobody is going to stone you for asking a question. Its Dumb statements that get many offside.
I co u I'd not explain the physics like @One Day... did.
Obviously speed kills in more than one context.
My .223 has killed plenty of pigs being what I had when i saw them. A good hit or shot placement does the job.i have also shot pigs with a lever action .357magnum handgun cartridge.

I try to liken the comparison to throwing a house brick at something or throwing a Besser block at something. Both will hurt. The Besser block might come in slow but the mass will hit hard if you are in range of it.

Besser block might be a Cinder block pending where you are from. Anyway Aaron, G'day from Australia.
 

BeeMaa

AH legend
Joined
Jun 11, 2017
Messages
2,714
Reaction score
4,298
Location
Eastern US
Media
99
Hunting reports
Africa
1
Member of
NRA Life Member, SCI
Hunted
Eastern US & RSA
It does have something to do with the attitude of the game being shot-a relaxed unsuspecting animal vs. alert/excited one-or a previously wounded one
I completely agree with @Firebird.
And this has been my experience as well.
Unsuspecting animals are more likely to DRT.
They are relaxed and don't have the adrenaline pumping.
Body chemistry/condition of the game animal is a factor.

Just think about yourself for a minute.
How do YOU react if someone tries to scare you?
If you know it's coming...you counter attack and mess with them.
If not...they got you.

If anything, this should make you want to be sneaky-sneaky.
The most quiet and sneaky of hunters.
Creeping up on an unsuspecting animal is my goal.
If I get a chance to shoot, that is awesome.
If not, the animal spooks and I have learned something else.
At least I have the satisfaction of knowing how close I can get.
Sometimes just being that close to game is the reward.
 

Shootist43

Gold supporter
AH ambassador
Joined
Apr 25, 2015
Messages
5,877
Reaction score
5,895
Location
Grosse Ile, Michigan
Media
25
Hunting reports
Africa
1
Member of
NRA
Hunted
Michigan, Texas, Missouri, Limpopo Province South Africa
Madis, I too want to welcome you to AH. We have a Forum for introductions, please use it to tell us a little more about yourself as a hunter. things like what have you hunted in the past, what kind and caliber rifles you own, do you reload. I've been a big fan of Nathan Foster and his writings for over five years now. He tells it like it is. My favorite rifle for Deer sized game is the 6.5 x 55 Swedish Mauser. His treatise on that caliber was spot on, at least in my opinion. Seeing the practical limitations for that caliber made me think that what he had to say about other calibers ,rifles, shot placement, rifle care and maintenance, etc. were equally well considered. His Practical Guide to Reloading taught me many things.
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
the bigger the animal it is, chances for hydostatic shock drop quickly. We can discuss this phenomenon for common north hemisphere game (white tail, elk, roe deer, red deer, boar etc), but in all reality the largest animals, dont drop on hydrostatic shock - like elephant, rhino, buffalo. There is something in body mass of animal.

I am also under impression that next lower weight level of animals (up to 600 kg), are not dropping to hydrodinamic shock as fequently as smaller ones. (up to 250 kg)

All, in all, yours is tricky question, I hope you will find appropriate and satisfactory solution!
Thank you, I do too. With regards to large animals and hydrostatic shock, Foster has the following to say on the subject:
When testing hydrostatic shock on Bovines [water buffalo], I have discovered that impact velocities of 2600fps with suitable bullet weights (and construction) produced instant poleaxe in a repeatable manner. However, in many instances Bovines would attempt to rise, the action of attempting to rise resulting in increased blood loss with death following within seconds.
From https://www.ballisticstudies.com/Knowledgebase/Effective+Game+Killing.html
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
Very few hard and fast rules in terminal ballistics imo. Lots of general guidelines. Anyone that gives a hard rule violates the prime directive to rarely use always or never.
I'd tend to agree with you, yet Foster claims the reverse. To wit:
Of the thousands of animals harvested during TBR tests, 2600fps has been the most common cut off point with repeatable results (reactions) occurring when deliberately testing the impact velocity of 2650fps versus the impact velocity of 2550fps.
From https://www.ballisticstudies.com/Knowledgebase/Effective+Game+Killing.html
In effect, he claims due to the large sample size, that there is demonstrable effect at 2600+ [small bores] vs. 2550-. Thoughts?
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
I believe speed and bullet construction/performance are factors.
I totally agree. There's a reason cup and core small bores .243-.308 sell in the millions every season for whitetail. It's a proven combo that works. I'm just looking for something a little more scientific and Foster is the closest I have found.
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
I too am a devotee of Nathan Foster. However I don't remember anything about 2600 FPS and DRT. I do recall something about brain shots and shots into a animals Thoracic Plexus (located between the heart and the lungs which is part of the Central Nervous System) and shots to the forward section of the spine resulting in instant kills.
It's this one:
Hydrostatic shock, in bore sizes from .243” up to .338”, begins to lesson at impact velocities below 2600fps and most modern high velocity sporting cartridges including the magnums gradually lose shocking power beyond 300 to 350 yards. Of the thousands of animals harvested during TBR tests, 2600fps has been the most common cut off point with repeatable results (reactions) occurring when deliberately testing the impact velocity of 2650fps versus the impact velocity of 2550fps.
From https://www.ballisticstudies.com/Knowledgebase/Effective+Game+Killing.html
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
If you're still reading this, and noticing a slew of replies by me in series, I'm rather taken aback at the number and quality of replies I received,. In an age when most new forum posters are treated to "STFU and GTFO n00b" I'm a little bit shocked. Thank you all. I guess this is what I get for making a drive-by post on a Friday afternoon after work and then leaving town to go hunting, only to come back to over a dozen quality replies. That'll learn me.
 

R.M.C.

Bronze supporter
AH enthusiast
Joined
Jun 28, 2020
Messages
410
Reaction score
599
Location
Northeastern Pennsylvania
Media
6
Hunted
U.S. and Canada
I think it's a crap shoot trying to figure out how to kill animals "right there" with projectiles. Some deer I've shot dropped and died almost immediately were damn near gut shot and others have had broken shoulders and destroyed lungs and went hundreds of yards. In my opinion if you want something to keel over instantly I'd go with a neck or spine shots. When a bullet is placed right on the spine there's no chance of the critter mule kicking and running away.
But spine shots do not leave alot of room for error so you must take them with care. I've shot deer, bears, elk, and boar from various calibers and speeds but can't say the "slower stuff" dropped any more animals than the 3000+ fps stuff did. The ones I popped in the head or spine folded up like a lawn chair. I attribute most other experiences with luck. Great idea for a thread!!!!
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
The .257 Wby made me a believer...

This is an interesting thread to me because it aligns with an experiment I purposefully conducted during a 2019 PG hunt. a fast enough hydrodynamic wave propagated through the blood system.
This is a really fascinating post that aligns with my thinking at the time of purchase for that aforementioned .25-06 of mine. I too was taken in by the .257 Wby for much the same reason as you describe and then proved in the field. I, however, went with a .25-06 for two reasons: ammo availability and legal reasons. Although I reload, with a family, job and too many projects, I seldom have the time to properly work up a load and sight it in. That and much of my hunting is very spur of the moment. Coyotes are legal 365 days a year where I am and I'll get texts from friends like this: "Can you come right now and shoot those yotes towards the NE woodlot at Tim's farm?". I can stop at any hardware, sporting goods, feed store and some gas stations and grab a packet of .25-06 loads that my rifle is sighted for on the way. And legally, in my county, we are not permitted to use anything over ".275 calibre" for small game (does that mean 7mm in UK terms .275 lands vs. .284 grooves or is a .270 Win legal at .277?). Confusing, to be sure.

That being said, I find the .25-06 lacking in the medium game stopping department, as I described in my OP and thus my post in the first place. Question you for you then: If you were to continue shooting game with your .257 in your experiment and racked up a reasonable sample size, say 100 animals, would you still be batting 1.000 on DRT versus runners? Is the 2-300 fps extra of the .257 over the .25-06 the deciding factor (assuming good shot placement and identical projectiles)?
 

WAB

AH legend
Joined
Oct 8, 2015
Messages
2,646
Reaction score
5,611
Location
Alabama
Media
90
Hunting reports
Africa
5
USA/Canada
1
Member of
DSC, NRA, SCI
Hunted
Zambia, Botswana, Mozambique, South Africa, Zimbabwe, Namibia, Scotland, England, Canada, Alaska, Ireland
Excellent question. The .257 wby has intrigued me for years. It seems like it would be an incredible long range caliber and well suited to mountain hunting for deer/sheep.
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
We should have started by welcoming you to AH.com Madis :)

This, I do with great pleasure :giggle:

Madis, I too want to welcome you to AH. We have a Forum for introductions, please use it to tell us a little more about yourself as a hunter. things like what have you hunted in the past, what kind and caliber rifles you own, do you reload.
Cheers gents, sincere thanks. This board is quite a change from what I am used to nowadays, as I stated earlier. And I'll take the time to introduce myself as you had suggested.
 

Madis

AH member
Joined
Nov 20, 2020
Messages
16
Reaction score
44
Location
Canada
Media
3
Member of
OFAH
Hunted
Canada
In my 40+ years experience, well-shot game animals indeed ran approximately half of the time, regardless of caliber or velocity, and medium bores starting at or around .33 indeed punched above their weight class with high SD bullets, even at sub-2600 fps velocities, through mechanical damage to the circulatory and/or musculoskeletal systems. This was why I selected the .340 Wby 250 gr for Moose, Caribou, Bear, etc. in Newfoundland and British Columbia for example.

But it was not until I recently experienced .257 Wby velocity, that I experienced reliable DRT effect out to 200 - 300 yards, and, truth be told, not too many cartridges achieve enough velocity to do this. In my own experience, even notoriously flat shooting "classic" calibers fail to do this: the 130 gr .270 Win is already down below 2600 fps at 175 yards; the 140 gr 7 Rem Mag at 200 yards, etc. It would be interesting to know how many of these "regardless of caliber or velocity" shots met the 2600 fps impact (emphasis: impact, not: muzzle) velocity threshold in the South Carolina study...

  • I choose fast / light / low recoiling calibers for up to 300 lbs. animals (I reckon the .257 Wby 100 gr TTSX to be close to ideal for small and medium plains game as well as mountain game, and it can easily reach to 600+ lbs. in a pinch);
  • I choose proportionally slower / heavier / larger recoil calibers for proportionally larger animals (my picks nowadays are .300 Wby 165 gr TTSX for large PG, .375 H&H for carnivorous DG and .470 NE for herbivorous DG).
I still love the big .340 Wby, but I reckon that a .300 Wby shooting a 165 gr TTSX that retains 95% of its weight (i.e. 155 gr) during expansion is every bit as destructive as a .340 Wby was when I adopted it 30 years ago, shooting a 250 gr NP that retained 60% of its weight (i.e. 150 gr) during expansion...
Yet another .257 fan I see, and with good reason. In my previous posts I discussed why I chose a .25-06 over the .257. Maybe I just should have bought the Weatherby...

Tangentially, the .257 was born about the same time as the .244 H&H and the David Lloyd rifle (Weatherby and Loyd having been contemporaries) and the concept with the latter rifle is very similar to Wetaherby's design ethos.

The-David-Lloyd-Rifle-6a-springer-vienna.com_.jpg
 
Last edited by a moderator:

Forum statistics

Threads
36,221
Messages
682,379
Members
62,430
Latest member
CXCMicah4
 

 

 

Latest profile posts

Rickmt wrote on Justbryan's profile.
What is your new shorter rifle? Thanx Bryan !
raamw wrote on neckdeep's profile.
Supply your address so I can get shipping Paypal Friend (no ) fee) is fine
Viral_SIGness wrote on Rifle57's profile.
Great person to deal with. Fast communication and quick shipper!
Sarg wrote on Philippe's profile.
Hello Philippe, did you get my PM that I sent you earlier ?

Regards Mark
raamw wrote on AfricaHunting.com's profile.
Can you advise me to properly post pix, sometimes I get it right sometimes not
 
Top