Sectional density and overall weight

is there no one that has insight on this matter ?
I have googled myself "stukkent" , everything is caliber only, no cross the board info.

I think there are too many other variables to be able to make a confident call on this one.

Speed plays a role. The 45-70 is said to penetrate better at lower speed than other .45 bullets at higher speed. It has to do with the target's resistance.

I think there are too many other variables to be able to make a confident call on this one.

My gut says this is the answer. It can't be single factor thing. SD is 'just' a ratio. You could have an artillery shell with a lower SD than a rifle bullet with a super high one and at the same velocity it would still penetrate your elephant/s better.

Ok - lets put it this way,the average heavy for caliber for say .270 @ 150 gr - .308 @ 180 gr- .385 @ 300 gr and say a .458 @ 400 gr all shot at their functional speeds.
Would the .458 and .375 end deeper just because there was more weight in motion, or would the .270 win because SD is so high?
Would the pure mass of a 400 gr bullet (2.5 x that of the .270) trump the good SD of the .270 because it only has 150 gr to work with.
My thought is that it surely must, because the .375 shoots through elephant's or reach's 1 - 2 m into it (I think)
The . 270 even shooting a 170 gr bullet with a Sd far far above the .375 bullet will not do that, or will it ?
Is it called momentum, weight in motion ? Does momentum count ?Will that cause the 458 to get deeper, even if its sd is less than the .270, the .270 just does not carry enough whatasaname.

I think there are too many other variables to be able to make a confident call on this one.

My gut says this is the answer. It can't be single factor thing. SD is 'just' a ratio. You could have an artillery shell with a lower SD than a rifle bullet with a super high one and at the same velocity it would still penetrate your elephant/s better.

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Yes, this is what I am trying to pose or question but lacking transmitting ability. Perhaps "is heavier just better, every time, every way, just deeper penetrating"

I just bought a 7x57, and I was disappointed to find that the .270 trumps it in almost every comparable way. I somehow thought that the 7x57 was this wonder penetrating caliber, but if Sd is used, the .270 is better, so I got to wondering if the 7x57 with same SD as .270 would penetrate deeper just because the same SD bullet is heavier and therefore regardless of the numbers it would travel deeper.

Penetration is the ability to overcome resistance as effective as possible.

It would mean something similar to the BC whilst travelling through air, but with more variables.

Any engineers on board?

I think there are too many other variables to be able to make a confident call on this one.

My gut says this is the answer. It can't be single factor thing. SD is 'just' a ratio. You could have an artillery shell with a lower SD than a rifle bullet with a super high one and at the same velocity it would still penetrate your elephant/s better.

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Yes, this is what I am trying to pose or question but lacking transmitting ability. Perhaps "is heavier just better, every time, every way, just deeper penetrating"

I just bought a 7x57, and I was disappointed to find that the .270 trumps it in almost every comparable way. I somehow thought that the 7x57 was this wonder penetrating caliber, but if Sd is used, the .270 is better, so I got to wondering if the 7x57 with same SD as .270 would penetrate deeper just because the same SD bullet is heavier and therefore regardless of the numbers it would travel deeper.

Why not wet pack test the 2 calibres and see the results physically? Not ideal medium but sure as hell better than any formula or equation surely.

interesting article on the subject.
Some notes: Double your weight and you double your energy, but double velocity = quadruple energy. It seems that velocity beats mass.
158 gr bullet/100 gr 9 mm bullet at respective near max velocity for bullet weight.
401 J - 296 ftlb / 558 J - 412 ftlb, thats 25% more energy for a 30 mass reduction and about 40 increase in velocity (915 fps/1360 fps)
https://webpath.med.utah.edu/TUTORIAL/GUNS/GUNBLST.html#2

So when Cody and I are on our bellies crawling through the thick stuff, it would be better to have 100 gr bullets than 158 gr bullets ?
When facing bushpig and warthog at close quarters, you want that bullet to travel as far as possible through target, often the shot is without choice from rear to stop a wounded animal from furthering away.
The above takes me back to Impala bullets - doubt they can be beat for sub sonic penetration ?

Problem there is that the faster the bullets go, the more inertia the impacted flesh have. This causes larger expansion on the bullet and either bullet failure or insufficient penetration with plenty meat damage.

It seems that tests give different results, depending on things like bullet type (lead vs mono vs cup&core vs FMJ), bullet speed, penetrated medium etc.

The only way to know for sure is to shoot one type of bullet at several speeds. Example: 139gr Hornady Interlock in a 7-08, 7x57, 7x64 and 7mm Rem Mag.

Then repeat the same test with a mono bullet, and yet again with FMJ bullet. The test would probably only partially possible with lead bullets due to the speed limit on lead.

Another possible test would be to get different bullets for one calibre, with equal weight, and shoot them at the same speed.

It depends much on bullet weight, design and speed as well as the target medium.

With my 357 Mag snubbie I experienced following vs a 9mm P:

• The 9mm with FMJ range rounds (124gr) penetrated better than 158gr Hornady XTP +P loads at 5m. We fired into conveyor belts; the 9mm penetrated the first belt and into the second; the 357 barely passed the first belt. Both bullets were not bent out of shape by much.
• The 9mm with FMJ range rounds (124gr) knocked over hinged falling plates at 7m-10m; the 357 with 158gr SWC hit with enough force to knock them down and they sprang back up.

The 45-70 has enough penetration to shoot through (kill) any African game; however hunters opt for the faster 458 calibres because of the "wallop" factor because the 45-70 (apparently) does not stop a charge.

The 357 Mag usually shot 158gr bullets until the FBI figured out that a 125gr bullet gives better performance for police work.

Regarding your 9mm question: you need both penetration and wallop. I would test a solid 9mm flat point if available.

From https://www.shootersforum.com/threads/penetration-the-45-70-458-magnums.9085/page-2?nested_view=1&sortby=oldest

Regarding medium;
At the Midwest Big Bore Seminar, we use two seperate stacks of wet pack for the penetration tests. They are 8 feet in length. We cronograph the shooters bullet/load and send him to the first stack which contains wet soaked newspaper. After firing we leaf through the paper stack to determine the wound cavity and bullet path. Mark where the bullet stops recover the bullet. We then assess the condition of the bullet and measure the distance traveled. It is the homogenous medium.
The shooter moves to the next stack and it is set up in a similar manner with the addition of a beef femur/ forleg bone placed in the stack at the 4" mark. This is to simulate the approximate position of most larger animals. After firing we make sure the bullet struck the bone, leaf through the stack to determine the wound channel and bullet path. We mark where the bullet stops, recover the bullet. We then asses the condition of the bullet and measure the distance traveled after the bone.
The addition of the bone will really change the condition of the bullet. It is really tough on bullets.
This gives us an idea of how the bullet will under some really extreme impacts.

During this shoot, we test deforming and non-deforming projectiles. As one might expect, bullets of the expanding variety perform all over the spectrum based on their construction and impact velocity.
There are so many variables in this field alone it will make your head swim. A manufacturer may have several differing styles of bullets construction. Over time you will see what each design acts like and certain velocities. Although some bullets designs will fail to penetrate as far or hold together as well as another manufacturer or design, it doesn't mean it's junk. It then falls to the shooter to select the appropriate application for the bullet. If you thought your bullet was an elk bullet and it turns out that it may be better suited for deer, now you know where to use it. I personally prefer a bullet that leans heavily to the tough side when shopping for expanding bullets. And as I get older, I'm less enamored with super pointy bullets. I guess my bullets are starting to look like me, bald and round on top and fatter in the middle.

Solids on the other hand are another story.
Lets start with the hardcast lead bullet. Alloy strength, velocity and nose design are all critical to the performance of the bullet. Even really tough lead is not very strong when compared to copper and brass. you can increase velocity until the impact overcomes the strength of the alloy and your bullet fails. I've shot some of Mr Garret's 45-70 stuff, and it is a real tough alloy. He has done his homework and offers a fine product.
So what happens to lead solids? An example is the 500 Linebaugh pistol with 435 gn WFN bullet.
1,000 fps--- wet paper penetration 28"
1,200 fps--- wet paper penetration 31"
It's worthy to note that with a 20% increase in velocity the penetration was increased by 3" or roughly 10%
Use the same bullet in a 50 Alaskan an run it up to 1,700 feet per second and it will overcome the alloy strength and blow the noes off. this reduction of mass yields less penetration. ( it might be noteworty, we shot some 480 grain WFN at 1,700 out of the 50 Alaskan in the plain paper, The bullets lost their noses and the recovered weight was 420 grains. The penetration was 24" I know it's not apples to apples, but noteworthy)

"AHA!" YOU SAY, "The reduction of mass is the cause of the penetration reduction. You still need to prove the more velocity equals less penetration with a non deforming solid"

First we need to realize that Mr Gates Slugs are not going fast enough to overcome the alloy strength. Therefore there is no reduction of mass with his slugs in wet paper. However, his slugs have a considerably larger meplat. The new Dixie's feature what I would term as a short dome wadcutter with meplat. It pushes or displaces with nearly the full diameter of the bullet. Hence his bullet is also recieving nearly that full area in material stagnation.
Others will note that the Dixie "doesn't have a high sectional density, like a 458". Well, well it has better sectional density than any 12 full caliber slug on the market (.196 compared to a 250gn Keith 44mag at .194), and better that some sabots. Mr Gates Dixie slugs are very impressive. I believe that he has a great thing going and has the description of their intended purpose, accurate to the letter. I believe they are a worthy purchase.

Let's eliminate the lead strength problem and use brass flatnose solids. Now we're talkin'. I've shot some of these. They are scary as to how far they will go. I've got some 338 Win Mag that are Barnes round noses turned to provide a 65% meplat. I honestly don't know how much wet paper it will take to stop them. The first time we did the penetration tests we used about 4 feet of paper, they would blow through that and head across the Illinois prairie. After 55" of paper 3" red fir 2x12 and 2"more paper we finally caught them. (I've added alot of paper to the stack and am now shooting an 8' stack of wet paper. using these solids they will go through 4" paper a beef femur and an adittional 72", yes 6 feet of paper) I'm sure you will say "See 2,400 fps penetrates better than the other bullets you mentioned" It does penetrate farther. but it has .08972 square inches of total frontal surface area, and .03801 square inches of surface area on the actual meplat. Compare that to the Dixie at .4173 square inches total. It displaces alot less material.

So, can I prove that this always happens? Can I prove at what velocity that this takes place? Can I prove it with new data that will be accepted? I'LL TRY!

Since you may realize that I dont wan't to be shooting through 10, 12, or 15 feet of paper with a high sectional density, high mass bullet. ( lots of work!!!) I think we can prove this with a lighter bullet. ( less mass ) Say, in the 458 dia.( less paper killed, less field dressing to do)
I'll do a bullet in the 350 grain range and work the loads and see what velocity things start to go south. I'll start with the 45-70 and since I'm sure we'll need more speed, I may have to rechamber the old Ruger No3 to 460 Weatherby. I think it'll work without having to change the ejector. If not I'll use a cleaning rod ejector.

The same bullet will be used throughout. Weight, mepalt, diamater. The only thing changed will be speed.
This will give us DATA that is form testing especially for this forum and I'll post my results here.
Fair Enough?

From https://www.marlinowners.com/threads/45-70-vs-458-in-penetration.16384/page-2?nested_view=1&sortby=oldest

"The whole thing is not 45/70 vs. .458WM.

The real question is:

When it comes to deep penetration into animal tissues, is there a speed above which energy starts being wasted into displacing tissues upon impact, therefore resulting in less overall penetration?

I believe that the answer is yes. Every unbiased and properly set experiment I'm aware of goes into this direction."

(EDIT: PLEASE READ THIS ^ THREAD!)

I am still trying to find out if a lighter smaller caliber, say a .270 160 gr bullet with a high SD of about 310 at 2600 fps penetrate deeper than a 300 gr 458 with a much lower Sd of 210 at same velocity. Will the 310 SD go deeper because of SD or will the 300 grain go deeper because of it being 300 grain versus 160 grain

I am still trying to find out if a lighter smaller caliber, say a .270 160 gr bullet with a high SD of about 310 at 2600 fps penetrate deeper than a 300 gr 458 with a much lower Sd of 210 at same velocity. Will the 310 SD go deeper because of SD or will the 300 grain go deeper because of it being 300 grain versus 160 grain

We shot a blueWB bull at 120m with a 308 Win, and 130gr Impala LWHV with approximately 2700fps at the muzzle. It went in at the "V" of the neck, and penetrated all the way through the body, getting stuck in the opposite hip bone. My guess is that it could have penetrated completely if it did not hit bone because the bullet was inbedded into the bone. Obviously, any 458 mono will achieve the same, being a mono.

The same shot with a 180gr Sierra Pro-Hunter at 2400fps usually do not penetrate as far, maybe 2/3 of the way.

A 458 Win Mag can push a Speer 400gr FP at 2400fps. I am pretty sure that it would shoot lengthwise through a large antilope like a blueWB.

A 458 Lott can almost reach 2300fps with a 500gr, and 2574fps with a 400gr A-Frame. My guess is that a 450gr SP or FP bullet should reach 2450fps, on par with the 308 with a 180gr bullet. The 458 Lott will most definitely outperform a lighter 308 or 270 bullet.

Interestingly enough, a friend of mine shot a lion at 40m, broadside on, breaking both shoulders. He used a 416 Rem with a 400gr Hornady DGX bullet. The bullet penetrated the carcass, but was stuck beneath the skin on the opposite side. The PH said it was normal with lions, due to the density of the muscles.

So if you look at it this way. All metal spheres have the same SD. If you drop a 1kg sphere or a 1g sphere from the same height onto a plank of wood, they will impact at the same speed, but the 1kg metal sphere will do a lot more damage because it has a lot more energy to act on the wood. Hence a heavier bullet will do the same to the meat.

So if you look at it this way. All metal spheres have the same SD. If you drop a 1kg sphere or a 1g sphere from the same height onto a plank of wood, they will impact at the same speed, but the 1kg metal sphere will do a lot more damage because it has a lot more energy to act on the wood. Hence a heavier bullet will do the same to the meat.

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THATS WHAT I WANTED _ NEEDED, could not format that myself. So we can conclude that a heavy 500 gr poor Sd bullet will by nature of its heavier nature penetrate deeper, greater momentum, carried energy, than the high SD 6.5 Creeds 130 gr bullet.

Correct?

So if you look at it this way. All metal spheres have the same SD. If you drop a 1kg sphere or a 1g sphere from the same height onto a plank of wood, they will impact at the same speed, but the 1kg metal sphere will do a lot more damage because it has a lot more energy to act on the wood. Hence a heavier bullet will do the same to the meat.

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THATS WHAT I WANTED _ NEEDED, could not format that myself. So we can conclude that a heavy 500 gr poor Sd bullet will by nature of its heavier nature penetrate deeper, greater momentum, carried energy, than the high SD 6.5 Creeds 130 gr bullet.

Correct?

Generally, it should be the case, but not always. Bullet speed, bullet construction,target medium etc play a role.

Generally, it should be the case, but not always. Bullet speed, bullet construction,target medium etc play a role.

That's the point. It isn't a one factor thing. There are more variables at play than we can probably guess. At best you can probably say that heavier bullets tend to penetrate more deeply than lighter ones into the same tsrgets

The 7x57 built its reputation for penetration due to Kalamojo Bell who used it on elephant.

But ... he dissected elephant skulls to understand his shot placement, and he shot from very close up - 15m or so. And he used those long, solid bullets at a moderate speed compared to what we can do now.

Generally, it should be the case, but not always. Bullet speed, bullet construction,target medium etc play a role.

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Ya - not interested in all the construction, medium etc just same same same, just wanna know if a 458 shoots deeper than a smaller caliber because of weight. a 180 gr .270 bullet will have a SD of "huge" , but will it out penetrate a .375 standard weight bullet into an elephant body.

Well, here is my take.

It depends on how much material has to be moved out the way and how fast it has to move out the way.

A small diameter bullet will out penetrate a larger diameter bullet at the same velocity and SD just because the larger diameter bullet has to push more material out the way.

Momentum (speed x weight) plays a big role in penetration. I can remember a picture showing a 300gr (375HH) solid in an oak board. It penetrated 57 inches. I doubt if a 170gr bullet out of a 270 will be able to do the same. Projectile choice and makeup will play a big role in penetration. A 416 Rigby outperforms a 458 Win with penetration. This calibre and bigger seems to be where the larger bore creates more resistance due to frontal area increase.

Momentum (speed x weight) plays a big role in penetration. I can remember a picture showing a 300gr (375HH) solid in an oak board. It penetrated 57 inches. I doubt if a 170gr bullet out of a 270 will be able to do the same. Projectile choice and makeup will play a big role in penetration. A 416 Rigby outperforms a 458 Win with penetration. This calibre and bigger seems to be where the larger bore creates more resistance due to frontal area increase.

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Yes it was a .458 problem which led to the 458 Lott being developed. The bottom line is I just want to know if my 7x57 shooting a 170 gr bullet will be a better penetrating rifle than my .270 shooting a 150 gr bullet or my .308 shooting a 165 gr bullet.
I wanted a slow and heavy rifle for big time penetration and bought the 7x57 for that, but then saw the SD of the .270 150 gr bullet was right up there past and with the 7x57 bullets and I wondered if the 7x57 was that much of a better penetrator than the .270
That lead to this post.

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The bottom line is I just want to know if my 7x57 shooting a 170 gr bullet will be a better penetrating rifle than my .270 shooting a 150 gr bullet or my .308 shooting a 165 gr bullet.
I wanted a slow and heavy rifle for big time penetration and bought the 7x57 for that, but then saw the SD of the .270 150 gr bullet was right up there past and with the 7x57 bullets and I wondered if the 7x57 was that much of a better penetrator than the .270
That lead to this post.

Simple enough - after all the speculation
You have both rifles - run the real world tests ..
Depending on the type of 7x57 rifle you have and it's age - and chamber ( short throat ?}
You may be able to load it to similar velocities to the 270 ( 6.858mm )

BTW ;
7x57 is not normally considered a slow heavy round

Standard industry loadings for the 7x57 are on the low side due to concerns with very old weapons ( small ring Mausers from before 1900 )

See SAAMI CIP data with max pressure ( will download a PDF file )

C.I.P. Homologation 7x57

CIP Pmax pressure 3,900 BAR = 56.565 PSI ( say 57,000 psi ) SAAMI is 51,000psi

Walter Maitland Dalrymple Bell used a 275 RIGBY ( same thing )

Here is a whole lot about him , his rifles , and the type of bullet he used

WDM Bell & His Elephant Hunting Rifles

Speaking personally, my greatest successes have been obtained with the 7 mm. Rigby-Mauser or .276, with the old round-nosed solid, weighing, I believe, 200 grs. It seemed to show a remarkable aptitude for finding the brain of an elephant. This holding of a true course I think is due to the moderate velocity, 2,300 ft., and to the fact that the proportion of diameter to length of bullet seems to be the ideal combination. For when you come below .276 to .256 or 6-5 mm., I found a bending of the bullet took place when fired into heavy bones.

“Karamojo” Bell on Rifles: In His Own Words

When archive.org is up again you may be able to find his books

Treeman may find some of his answers in the above ?

Chat on bullet performance by Ron Spomer.

BTW ;
7x57 is not normally considered a slow heavy round
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Jaaaaaaaaaaa Newton, this may be the part I got wrong, dunno why, but somewhere in my past the 7x57 became embedded as "slow and heavy"
Some conversation somewherelong ago, stored incorrectly.

I think that this is the one you are looking for

Bell used German DWM 7x57 ammo 175gr round nose FMJ

7X57 MAUSER SILVER BULLET DWM 1913

Source for 7mm Solids

No idea where you would get round nose solid FMJ bullets today ?

Still you can get these ..

11,7 g / 180 gr Scenar-L OTM GB554

Perhaps not so good for Elephant ?