This question arose when I wondered what I would do if I bust my 9.3x62 the day before my upcoming Moose trip.

Given a 6.5x55 with a 140gr speer hot core bullet at 2,700fps or a 7x57 with a 154gr Hornady RN at 2,650fps with identical accuracy in identical rifle which would you choose? Or are they so far off the mark you'd choose to lose a day's hunting to buy some more suitable factory ammo (eg Norma Oryx) and rezero.

Or just for fun what if they had identical bullet weights at identical velocities eg both 156gr (10gram) Norma Oryx - would you go for the length of the 6.5 or the cross section of the 7mm or say what the hell and flip a coin?

No doubt I would take the 7x57. The longer the bullet, the greater the chance of it turning or tumbling after impact. When that happens, the bullet will come apart, penetration will disappear and the vitals will not be reached.

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Gerard Schultz
GS Custom Bullets

Flip a coin!

My vote would be 7 X 57.

Id go with the 7x57 any day, and with the 175 gr. bullet you would never know you broke your 9.3....

I have never been impressed with the 6.5 anything....

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

No doubt -- the 7 X 57. But I would try to work up a load with a heavier and preferably "premium" bullet.

Given the choices you�ve allowed, I will have to go against the grain here and vote for the Swede � but it is splitting hairs.

Contrary to what Gerard said, long heavy bullets are exactly what gives a cartridge good penetration.
Ask any Canadian who hunts Moose with a .303 and he�ll tell you he uses the 215gr.
Bell shot over a thousand Elephants with 6.5�s(160gr), 7mm�s(173gr) and the .303(215gr) amongst others, and in all instances he used these long parallel sided bullets � because of their ability to penetrate��.an Elephant.
Other great penetrators were the .318 Wes. Richards and the 333 Jeffery, what bullets gave them their reputations, I hear you ask���.the 250 grainer and the 300 grainer !

All else being equal high sectional density (long bullet) equals better penetration � and the 6.5/140 has a higher BC than the 7mm/154, just.
A 175gr in the 7x57 as Ray and Mike said would be a much better choice though.

Bush baby

1894. I think more moose in Sweden are shot with the 6,5x55 than with all other calibers combined, at least it�s not far from that. As a result of this love for the 6,5 the bullets, both Norma Oryx and Lapua Mega, are said to do excellent work in moose. FWIW my moose rifle is a Brno602 in 458WM and I just upgraded my dad�s 30-06 to a 9,3x62... I only recommend peaguns for peas AKI

My choice? The 7x57 with a 175 gr. bullet. Considering that the velocity will not be that high, I'm not completely sure a premium bullet is necessary.
If I were to use the 6.5, I'd use a 156/160 gr. bullet. Moose are big, and penetration is paramount. JMHO.
Paul B.

Bush Baby,
All the great penetrators you mention are round nose, flat base bullets. As is the 154 gr Hornady. The 140 grain 264 bullets are all spitsers and some also have boattails. Linear penetration has very little to do with sectional density. It has everything to do with bullet shape after impact, momentum and energy. Given the two choices of bullet set by 1894, the 7x57 will be the reliable one and the 6.5 may or may not get the job done.

Long for caliber bullets have a reputation for bending and turning and even complete failure if driven hard enough, and I will take a shorter bullet for linear penetration any day. I have done a small amount of experimentation around this subject.

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Gerard Schultz
GS Custom Bullets

I would go with the 7x57 and 175gr bullet at 2500fps this would be a good moose load

Flip a coin. I've seen a helluva lotta moose shot with the 6.5x55, all of them dead... Never seen a 155-160 gr 6.5 bullet do what Gerard says they might, although the bending issue seems to be quite common with non-expanding bullets on large animals.

I wouldn't feel handicapped with either chambering. Given a .308 w/ 165 grainers though, I'd be reluctant to take shots I wouldn't hesitate to take with the smaller calibers.

I've shot with the .375 H&H too, and there seems to be more reaction from the animals than with the 6.5 - they don't die any faster given similar placing of the bullet, but they seem to dislike the penetration more... Hitting the right spot is far easier with the lighter kicking flat shooters, that's why my 9.3x57 doesn't get used much.

-- Mats

Definatly the bigger bullet for moose even given the hypothetical. Now if your game was antelope...

[This message has been edited by Wstrnhuntr (edited 10-13-2001).]

Since there are only two options here, I would take the swede. The reason here is the sectional density of the 6.5 is higher and that translates into penetration and retained weight. Simple as that!

I do not wish to offend anyone here with the following opinion. As they say, "Just an idea, use it, don't use it."

Sectional density figures probably served a useful purpose when most all bullets were of similar construction. As a parameter in isolation of other factors that determine penetration, it is singularly useless as an indication of the ability of a bullet to penetrate.

By way of example, the sectional density of a 460 grain 6.5mm bullet (should it exist) standing on it's base on the loading bench, is 1.00 but it just sits there. Even a bb dropped from shoulder height on the loading bench will have more penetration than the 6.5. Another example: Two 6.5 mm bullets of the same weight fired at the same speed, but one is a solid copper roundnose and the other a match hollow point. They have the same sd, but I will not place bets on which one will penetrate best.

I would go with the 7x57 only because I have hunted a lot with a 7-08 and, with proper bullet selection, would not be reluctant to go after anything (in the USA) except the big bears.

I agree with Gerard, If your shot is at a bad angle the longer bullet can bend and tumble I have seen this even shooting through wet news papers. I think for bigger game the 7MM bullet is a better choice, and for B.C. is it all that important at shots from 300yards and under? I think not. My choice would be a 280 Ackley with 160 or 175 grn bullets.

Thus far we have 8 for the 7x57 (albeit most with heavier bullets) 2 for the 6.5x55, two for either and one inconclusive.

I've had to do a bit of reading in between the lines.

1. I've set greater store by the natives.

2. I believe the two are not greatly dissimilar but local conditions favour the 6.5 because

3. If I have to get a tougher bullet the 6.5x55 156gr load is available in every gun shop in Sweden and my host shoots it so I could even beg some off him. Norma do not make anything tougher for the 7x57 yet and I'm not confident of my ability to get other makes at short notice

I've had the 6.5 for a lot longer and believe that any gremlins have been shaken out (touch wood)I'm also half Swedish so brand loyalty comes into it!

So if I bust my 9.3 I will be taking my 6.5x55 - apologies for going against 8 of you but given my inability to develop 175gr loads in less than 12hours and my lack of confidence in finding them in Sweden I think you'll understand.

[This message has been edited by 1894 (edited 10-15-2001).]

OK Gerard, nice posts.
I�ll give you the fact that the 140gr/6,5 is pointed and may not penetrate as well as the 154gr/7mm round nose � point taken.
Also that a bullet�s Sect.dens. taken on it�s own is �is singularly useless as an indication of the ability of a bullet to penetrate.� � of course.
Obviously a 460gr/6,5 bullet just sitting on a bench will do nothing, it has no movement and therefore no momentum.

However, within a given calibre, and assuming bullets of different weight but same shape (round nose) and equal velocities, the heavier bullet will have greater momentum and energy � which as you pointed out, has everything to do with linear penetration.
Even as you reduce the velocity of the heavier bullet, this situation will continue � up to a point of course.
Sometime ago (1920�s I think) the BSA company unwittingly proved this, they loaded their new 33BSA with a 165gr bullet at 3000fps, it was a dismal failure � just couldn�t be relied upon to penetrate on anything but broadside shots, but the 318 WR and it�s 250gr bullet at 2400 was a real champion.
I understand that both were conventional soft points and of different shape (spitzer and r/nose), but even if they both were of the same shape and construction (even if they were solids), I doubt the results would have been any different.

Quote: - �Long for calibre bullets have a reputation for bending and turning and even complete failure if driven hard enough�. A 250gr/308 driven at 3200fps might bend or break, but what about a 250gr/338 bullet at 2500fps?
What is long for calibre? And what is driven hard?

As you yourself acknowledged, �All the great penetrators you mentioned are round nose��.
Question; What made them great penetrators?
Answer; Long heavy bullets (high sect.dens.) at moderate velocities (2200-2500fps) and round nose bullets � preferably with parallel sides.
As a final test lets take one very p$$$$$ed off Jumbo bull. Stand in front of him � 20 yards away � making comments about his mother�s virtue.
Now take two 375 H/H rounds for your rifle � one loaded with a 185gr solid (BC=.188) at 3250fps and the other a 300gr solid (BC=.305) at 2550fps. Both have equal energies.
Now if your right, you simply select the 185gr load and let fly, sending old grumpy to meet his mother.
If you�re wrong however�����well you better load that 300 grainer in a hurry!

Nuff said. I rest my case.

By the way I hear the Big shot show has been postponed, are you attending this year and do you know when it is? Always like talking to you, I�ll come around and we can carry this fun on some more.

Bush baby

Bush Baby,
There are three parameters that, together, determine penetration. Bullet shape after impact, momentum and energy.

"within a given calibre, and assuming bullets of different weight but same shape (round nose) and equal velocities, the heavier bullet will have greater momentum and energy"

You are correct of course, but lighter bullets are not meant to go at the same speed as heavier ones within a particular caliber. They go faster. Given two bullets of similar robust construction, this allows us to equal the momentum of a heavier bullet with a lighter one, and when that happens, the lighter bullet has more energy and results are better.

"they loaded their new 33BSA with a 165gr bullet at 3000fps, it was a dismal failure � just couldn�t be relied upon to penetrate on anything but broadside shots, but the 318 WR and it�s 250gr bullet at 2400 was a real champion." and "a 185gr solid (BC=.188) at 3250fps and the other a 300gr solid (BC=.305) at 2550fps. Both have equal energies."

Correct again, but the light bullets in your examples fail, not because they are light, but because they have much less momentum. Equal energy does not an equal bullet make.

"What is long for calibre? And what is driven hard?"

Long for caliber is a bullet that is longer than what is dictated by the rate of twist of the barrel for stability. Driven hard is any speed that will cause the particular bullet to fail completely. So a spitser boattail of 180 grains could be too long for the caliber, but a 180 grain flat base round nose in the same caliber can be right. Similarly, a no name brand jacketed lead bullet impacting at 3000 fps and turning into itty bitty pieces, is driven too hard, but a similar length and caliber monometal bullet, impacting at the same speed or faster, gets the job done.

All the great penetrators you mentioned were always matched to the correct rate of twist for the length of bullet. That is in fact what made them great, not their weight.

"Now take two 375 H/H rounds for your rifle � one loaded with a 185gr solid (BC=.188) at 3250fps and the other a 300gr solid (BC=.305) at 2550fps. Both have equal energies. Now if your right, you simply select the 185gr load and let fly"

I said I will take a shorter bullet for linear penetration, not the shortest bullet. The length of the bullet must match the rate of twist and preferably be a bit shorter than required. Given your angry ele example and a 375 H&H, I would not use a 185 grain solid, but a 270 grain solid and make it fly. Compare the weight, speed, momentum and energy of these 375H&H solids at 50 meters: 270gr @ 2980 = 112 / 5105, 300gr @ 2580 = 101 / 3736, 350gr @ 2350 = 110 / 3793, 380gr @ 2200 = 112 / 3596. Want to bet which one will do best?

The Safari Africa Exhibition has been postponed with no future date given. The Aim Shooters Show is on at Kyalami in the first quarter of next year and we have booked a stand.

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Gerard Schultz
GS Custom Bullets

You guys are makin' my head spin.....

Why would a roundnose bullet penetrate better than a spitzer?? I always thought it was the other way around because the round nose starts expanding quicker? (thus slowing it down)

Try this scenario

You have a 140 grain 6.5x55 using a Speer Grand Slam bullet, fired at 2600fps. It has a SD of??

You also have a 180 grain 30.06 Grand Slam fired at 2700fps. It has a SD of ??

For argument's sake, assume the bullets expand in the same fashion. Which would penetrate further, and why???

This entire disgussion seems to be based on the assumption that either caliber mentioned will need all the "penetration" they can muster up to do the job on a moose. Why? Isnt a ballance between expected shooting distance and required energy just as important as penetration? Also I too would like to know how it is that a round nose is supposed to have more penetration than a spitzer. Since a RN is designed for rapid expansion @ low velocity isnt that like saying an expanded bulled will penetrate more than a FMJ. Perhaps you mean a jacketed RN like the tungsten grand slam..?

Load availability seems like a good reason to choose though..

[This message has been edited by Wstrnhuntr (edited 10-16-2001).]

Gerhard just as a matter of interest what formula are you using to calculate momentum, I always thought it was:

Momentum = bullet mass x velocity (divided by 1000)
Am I right? If so it would give the following results in weight, velocity, momentum and energy.
270gr @ 2980 = 802 � 4614 f-lbs
300gr @ 2580 = 774 � 3803 f-lbs
350gr @ 2350 = 822 � 3658 f-lbs
380gr @ 2200 = 836 � 3470 f-lbs
Although for the .375 H/H a 270gr @ 2750 = 742 - 3913 is more realistic as max. velocity.

Correcting my earlier errors and now matching momentum figures (in barrels of suitable twist rate). Can we say that a 235gr bullet @ 3300fps (774 � 5087f-lbs), which has the same momentum as the 300gr load above, but the required higher energy, is now a better penetrator than the 300gr load � assuming bullets of equal shape and construction?

As the lighter bullet sheds velocity on impact (which it will do faster than the heavier bullet) will this not dramatically reduce its momentum and energy, and thus it�s penetration?
Due to its lightweight, this load needs only lose 425fps to completely nullify its energy advantage � which is not hard to do when hitting something thick skinned and big boned.

Sorry, but the theory that light short bullets driven very fast are the equal of heavy long bullets for penetration doesn�t hold with me. It may work where bullet masses are close (270gr vs 300gr), but it doesn�t seem to hold up at the extremes.
Lets agree to disagree. JMHO

**********************************************************
Aaron,
The formula for calculating sect.dens. is:

Sectional density =bullet mass divided by bullet diameter squared x 7000
308/180gr = .271 (momen. = 486)
6.5/140gr = .287 (momen. = 364)

The 180 will penetrate deeper because despite its lower SD figure, it is nearly 30% heavier and 100fps faster, giving it a MUCH higher momentum figure.
I think round nose bullets penetrate deeper because they shed much more velocity in flight and therefore impact at a lower velocity, causing less break-up and retaining more weight. Also their normally longer parallel sides allow them to travel in a straighter line.
There is a school of thought that says boat tails actually promote jacket-core separation, and obviously no round nose bullet has a boat tail.

Bush baby

[This message has been edited by Bush baby (edited 10-16-2001).]

[This message has been edited by Bush baby (edited 10-16-2001).]

Dare I say that if you looked at these bullets you'd be hard put to tell what all the fuss is about - one is pointy and the other is a little fatter, blunter but the same length. To all intents and purposes momentum is the same at the range I will be shooting at.

To me there relative effectiveness will hinge on their ability to penetrate and expand and to cope with the undesirable event of hitting a big bone.

It seems to me that their how you rate them depends on whether you believe in 'hot core' or 'interlock' and whether the slight extra weight of the 7mm is offset by the fact that it may expand sooner than the spitzer thus negating any weight advantage.

I will try and put them through my ballistic moose and see how they stack up. This will be horrendously unscientific as I only have space for one shot each but should nevertheless give an indication. Anyone like to place bets as to where I will recover them

0.5inch wet phonebook
2times 0.75inch ply
approx 13inches wet phonebook
2times 0.75inch ply
0.5inch wet phonebook

Range will be 50 yards. The 9.3 286 gr nosler at 2200 or so made it to half way through the last sheet of ply - I hope these get to halfway through the vitals ie the middle section of the wet phonebooks.

I've got my money on the 'lil swede.....9 inches into the wet phonebooks.
I'll say the Hornady RN makes it 8.25 inches into the wet phonebooks.

If I win, everyone on this forum HAS to send me 5 bucks.

1894

Yeah you�re right,
Gerard is very knowledgeable and a visit to his website will show that he certainly does his homework. It was fun and a nice learning experience, but we did stray from the topic a bit��..sorry.

Bush baby

BushBaby,

You go right ahead - it's fun to read anyhow you were so near in your predictions you deserve $5

[This message has been edited by 1894 (edited 10-17-2001).]

Well yesterday despite the wrath of the wife I reinstated the ballistic moose. The phonebooks were redoused and this time housed in a cardboard box for convenience (and perhaps simulating skin?) and at 50 yards I let rip.

The result - A DRAW!

The hornady made it 10 inches. It weighed 103.7gr and was a perfect mushroom at about 0.53" not including some protruding jacket only on one side. It penetrated straight (all shots were at 90% to the face)

The speer made it 10.25 inches ie the same given the lack of scientific uniformity. Hurrah for the Swede! But it weighed 52.2gr (sob) and had a mushroom that looked like a wiped out partition or X (but with the jacket remaining behind it) and was 0.4 inches in diameter again excluding one off bit of jacket.

Examination of the 'wound trail' was interesting.

With the 7mmRN the initial 0.5inch wet phonebook (shoulder muscle)showed a noticable shock effect on entry. Thereafter the wound trail was more or less uniform.

The 6.5mm spitzer showed a neat hole in the initial muscle and a uniform wound trail apart from the second wet phonebook after the 'bone' which had a big cavity say about 1-1.5 inch width for about 2 inches, thereafter a normal narrow channel.

My supposition is that the RN provided tissue disruption/shock from the instant it hit and that it started to expand ie 'set up' literally immediately but did so in a controlled fashion. The softer and thicker copper jacket and interlock allowed the mushroom to stay together so a pretty much parallel sided wound channel of uniform width resulted.

With the spitzer I believe the expansion did not start until later and that because the velocity was greater (maybe by as much as 100fps, and the jacket being thinner and harder,expansion when it did occur did so rapidly and with considerable weight loss (hence the cavity)The fact that the hot core process allowed the jacket to retain it's core despite being wiped back for well over half it's length allowed it to continue to penetrate.

Uniform but slightly wider throughout wound channel for the 7mmRN, narrower throughout but with large wound cavity post shoulder for the 6.5mmSP.

If this accurately represents a Moose then I think the Swede would have had more effect as that large cavity was at heart depth. Such a lack of control would worry me however as to my eyes it seems a less dependable mechanical phenomonen.

So have I changed my mind? Yes and no, I thought as they were it was a case of flipping a coin and I still think it is. If there were no ammunition availability or dependability issues I'd definately take the 7mmRN but there is so I'll still take the 6.5SP but only if the 9.3 breaks. The wound channel at the widest of the 6.5 is the same as the narrowest of the 9.3! Bigger bullets do indeed make bigger holes.....

[This message has been edited by 1894 (edited 10-17-2001).]

Bush Baby,
Bullets with equal momentum will give equal penetration if all else is equal such as diameter, 100% weight retention and nose shape. That is not theory, it is fact. It also works with bullets that differ widely in weight and those that are closer together. So agreeing to disagree does not change the fact that you are labouring under a misconception. Sorry to be blunt but science is on my side here.

Both your calculation methods (momentum and energy) are incorrect.The correct formula for calculating momentum is weight in lbs multiplied by velocity in feet per second. Therefore a 270 grain bullet at 2950 fps has 270/7000x2950= 113.79 lb-f/s momentum. I do not work this all out manually every time. I work with these values several times a day and use ballistic software. By the way, 2950 fps is a totally realistic speed for a 270 grain bullet. You should try them some time

Your example of a 235 grain bullet at 3300 fps and 300 grain bullet at 2580 having the same momentum is right on the money. If neither bullet breaks up and both have the same nose shape, penetration will be very similar. There are other factors to consider such as the higher pressure generated on the front of the faster bullet and the higher energy level of the faster bullet that adds to the volume of the permanent wound channel.The bottom line is, however, if two bullets retain weight well after impact, and have similar momentum levels, the bullet with more energy will be more effective.

There is no such thing as momentum generated by a light bullet being different from the momentum generated by a heavy bullet. If the numbers are equal, they are equal.

1984,
The ballistic moose is a good idea, I will use it also for comparative testing. As far as the Swede and the Mauser are concerned, given the ballistics involved, the 6.5 will do better than the 7x57 beyond 150 meters. So it is really very close.

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Gerard Schultz
GS Custom Bullets

Sounds like you'll need to dig up some of the discontinued Hornady 140 round noses in 6.5, don't look at me I'm all out. In either case it sounds like moose is what's for dinner. I like the 6.5s best because mine have always been a bit more accurate than my 7s. My Swede being the lone exception, it just flat refuses to shoot. No matter, I've got a pair of .260s.

Gerard,

I do wonder if ply is a good approximation for bone? I'm sure I read somewhere that it was.

You all have spent WAYYY to much time and effort on this one. Here's how you make your choice:

Eeeeny, Meenie, Miney, Moe...

No Sir! The longer the bullet, the straighter and more stable it will be in penetration after impact.

1894,
Ply is probably as good as it gets because of the consistency and repeatability when comparing different bullets.

JK,
I do not wish to offend you with this, but there is no factual basis that supports your statement. Have a look at the picture at http://www.zibycom.com/members/002245268/Site2/375380gr.html as well as the picture in the article at http://skyboom.com/gscustom/index19.html for the facts about long, thin bullets.

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Gerard Schultz
GS Custom Bullets