Sectional density and overall weight

[Ds J]

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!)

[Treeman]

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

[Ds J]

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.

[Againstthegrains]

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.

[Treeman]

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?


 

[Ds J]

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.

*******************************************
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.

[oafpatroll]

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

[Ds J]

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.

[Treeman]

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

[janfred]

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.

[Tripodmvr]

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.

[Treeman]

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.

[Newton]

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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 ?

[Tripodmvr]

Chat on bullet performance by Ron Spomer.

https://www.youtube.com/watch?v=yWAao9xosrg

[Treeman]

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.