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Howdy Gents,

Somebody please help me understand what im looking at here.

Ive always spent my time with .30-06 and medium bore cartridges, and never really had any need for the small-bore magnums like the 7mm Magnum, .270 Weatherby Magnum, .264 Magnum, etc.

However, when I compare them in all the reloading manuals, its interesting to note, that the max loads for all of them, per the same relative bullet weights, perform nearly the same as the .30-06 max loads.

At the most, there might be an occasional difference of about 200fps from the .30-06. But for the most part, they were relatively the same.

With this, I find myself wondering - Whats the point of these magnums?

Am I seeing things here? Are the reloading manuals misprinted?

Now, I fully acknowledge the performance increase that nearly all .30 caliber magnums have over the .30-06. However, my confusion comes more from the comparison between .30-06 and the magnums which are less than .30 caliber.

For instance, the comparison between .30-06 and 7mm Remington Magnum. Or the comparison between .30-06 and the .264 Magnum.

The velocity numbers are shown to be about the same per bullet wieght, and I guess I just wasnt expecting that.
 

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I suppose, truth be told, that a rifleman is complete with a .22LR, a 12 ga shotgun and a .30-06. I have taken elk and deer with both my .30-06 and my 7mm Rem Magnum. The critters didn't wave any scoring placards that read "Not enough power" or "Too much power". But we are fortunate in that we have so many to choose from. And the Arms companies would probably be in dire straits without the plethora of cartridges and guns to choose from. And gunwriters would kinda be a boring lot indeed if all we had was the .30-06. Forums like this would probably be downright boring without all the choices.

So, what did I do? I gave my beloved 7mm Rem Magnum to my son and I kept my .30-06. Both are incredibly accurate. I just happened to keep my .30-06 1903 Springfield because I rebuilt it in 1963 and it's a part of me. The Big 7 is on a Winchester M70, push feed no less. Shot a partridge one year with that 7, up in the mountains of Colorado on an elk hunt. Two partridge got up in front of me and just from instinct I pulled up and fired. Knocked the head off the bird. But I'm getting old, I guess, never even fired on the 2nd one.
 

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The 30 caliber, or .308" diameter bullets, are unique in the broad range of weights they cover and the huge variety of bullets available for it. This allows you to compare it, with like bullet weights, to quite a few other calibers, making what seems to be a valid comparison. It really isn't, though, since there are many other factors that contribute to bullet performance, besides the weight. You're better off determining the sectional density of a given bullet in one caliber, then comparing it to a bullet in another caliber, with a similar sectional density. (Would you rather get hit in the chest with a 5lb sledge-hammer, or a 5lb bag of Styrofoam, traveling at the same speed?)

It is also somewhat important to take note of the ballistic coefficient of a given bullet, when comparing it to another. Case in point:

A .277" 130gr SPBT-style bullet will have a sectional density of ~.242 and a BC ~.430. When launched from a 270 Weatherby, it is capable of ~3350fps. The .308" 125gr SPBT-style bullet will have (approximately) a SD of .188 and BC of .366 and from an '06, you might get 3250fps from it. So, it's only 100fps less. The difference between these two will be evident at truly long ranges of 300 yards, and more. At those extreme distances, the sleeker .277" bullet will have retained more velocity, and thus energy, plus the higher sectional density means it will (typically) hold together better and penetrate more.

To be succinct, the difference between any two "modern", cartridges is not going to be all that significant. Some will have a little flatter trajectory and some will have a little more energy, but when you take a good hard look at the numbers, they are all remarkably similar. From .243" up to about .323" (excluding the full-length magnums), you can pick just about any cartridge designed in the last 110 years, or so, and it's surprising how alike they really are to one another. Perhaps the best illustration of this is the 6.5x55 Swede and any of the newer 6.5 wundercartridges, like the 260Remington, 6.5x284, 6.5 Creedmoor, etc. Once any of them spit a .264" diameter bullet of their respective barrel, they are all dang near identical!

The difference is not in the "numbers", but in the performance of a well-constructed bullet that is an ideal weight, for a given caliber.

Great question/observation. :)
 

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A simple fact often overlooked when comparing the .30-06 to various magnums is the fact that originally, almost without exception, velocities of the magnums were measured in 26-inch barrels. Many folks today don't want a 26-inch barrel, and when the comparison is made in 24 or 22-inch barrels the difference is much less dramatic.
 

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I noticed this quite some time ago when I "needed" a deer rifle. The area I hunt in used to be shotgun only and now has since been opened up to rifles. I did some "hard" studying and came to the conclusion that, for me anyway, the 7mm-08 would be the most pratical thing around. Virtually the same trajectory as any of the magnums. And could be feasible for varmints as it was almost as flat-a-shooting as any of the varmint calibers are.

I still don't have a 7mm-08. Bought a bunch of other guns. Shotguns, muzzleloaders, varmint rifles, 22lrs, etc. But no "big game" rifle yet. My Mossberg 500 seems to do well enough for me. And even though it's been some 10-15 years of me deciding that was what I need I'm still looking, though I have added a few calibers to the list. The 338-06, 35 whelen, and a 338-360 rem mag. But the 7mm-08 would be the most practical for me in all reality...

The magnums are certainly stronger than their non magnum kin calibers. A 300 win mag will certainly outdo a 30-06. But the trouble with some of these magnum calibers is that in order to truly use their potential you need longer barrels (of which no one really makes one) combined with much heavier bullets. I see myself with a 30-06 with a 24 inch barrel and 165 grain bullets, not a 300 win mag with a 30 barrel with 220 grain bullets while hunting deer. And the other problem with the mags, is even if you take a 378 weatherby mag and compare it's killing power on a deer versus that of a 257 roberts. A 257 roberts with kill a deer instantly. A so will a 378 weatherby. So what's the difference besides recoil? Little really. But with an elk, it's easy to say that a 338 win mag will outkill a 257 roberts at 400 yards.

But the real reason why people get the magnums....Why are people buying Camaros, Mustangs, and the Chargers? I don't know other than that they are pretty freaking cool. I'd love to have a Ruger 77 chambered for a 300 RCM with a fancy scope, even though a cheap mossberg chambered for the 7mm-08 and iron sights will do just as well as the Hunydai accent will get you to work just the same as an Infinity 35.

As terrible as our economy is, we are still faring quite well as a species. We have great excess (even those who have no jobs are faring quite well compared to those who were "well off" around the birth of our country) and if you can get the "cooler" gun, go for it.

But why are the magnums only a "little" bit better? Well, you want to carry a normal sized rifle for starters. And basic mechanical physics will only get you so far before the law of diminishing returns starts to take effect. The fact is that the 30-06 and the 308 famlies are "magnums." Just compare them to the 30-30WCF and the 35 remington. The difference between them is very real and well before the law of diminishing returns.

I know my response is a bit of a "dance around." But sometimes it's hard to make reason out of illogical choices.
 

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Your right Sinbad! I'm thinking of getting rid of 50 some long guns and keep only a .22, 12 gauge O/U,and a .308 Win. Now what can you say about handguns? Sinbad confirms that I should have listened to my wife long ago.
 

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The magnums are great for their intended use but if you hunt thick woods with small fields and a clearcut now and then they aren't much fun. They don't give much increase in performance once the barrel is cut down to 18-20 inches for handiness. Sure is fun to watch the powder burn beyond the muzzle.
 

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Discussion Starter #8
I suppose I had assumed, that the magnums, based on the nature of their existance, wouldve shown a much larger velocity advantage over the .30-06. I was surprised to find the opposite was true.

Regarding the long-range aspect, for example, Ive found only minor difference in trajectory from bullets in both .30 caliber and 7mm when both were fired from these same published velocities.

Honestly, there are plenty of varminters who use the Hornady 110gr .30 caliber V-Max with good success at long ranges. Ballistic calculators show that the flight path of that particular bullet really doesnt start sluffing off untill well past 400 yards. .30 caliber bullets as a whole, have a solid track record out to ranges of 1000 yards.

So with this, Im also left scratching my head over the lack of differences between the .30-06 and the 7mm Magnum.

But agreed, when comparing load data, there are so many similarities between .243 and .323 calibers.

This has become both a perplexing and fascinating discovery for me, especially when considering the trends in cartridge popularity over the last 50 years or more.
 

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Welcome to the forum. Rules are to join in, have fun, and be polite.

The issue of magnums comes down to purpose. Many of the older magnums run 200-300 fps faster than the '06, while the .300 RUM and .30-338 will run 500-600 fps faster with same weight bullets. About 50% more energy. However, in target shooting the interest in magnums is not in same-weight bullets. It's in running heavier bullets with higher ballistic coefficients fast enough to stay above the transonic velocity range all the way to 1000 or even 1200 yards. Even a .300 Win mag running 210 grain MatchKings will have a full third less wind drift at 1000 yards than a .30-06 shooting 175's, which the two cartridges can get to similar velocities. I've watched this at work at Camp Perry repeatedly. A quarter or a third less wind drift may not sound like a big deal, but that can still move a shot a couple of scoring rings closer to the center if a surprise gust of wind comes up at the last moment.
 

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Welcome to the forum. Rules are to join in, have fun, and be polite.

The issue of magnums comes down to purpose. Many of the older magnums run 200-300 fps faster than the '06, while the .300 RUM and .30-338 will run 500-600 fps faster with same weight bullets. About 50% more energy. However, in target shooting the interest in magnums is not in same-weight bullets. It's in running heavier bullets with higher ballistic coefficients fast enough to stay above the transonic velocity range all the way to 1000 or even 1200 yards. Even a .300 Win mag running 210 grain MatchKings will have a full third less wind drift at 1000 yards than a .30-06 shooting 175's, which the two cartridges can get to similar velocities. I've watched this at work at Camp Perry repeatedly. A quarter or a third less wind drift may not sound like a big deal, but that can still move a shot a couple of scoring rings closer to the center if a surprise gust of wind comes up at the last moment.
And what is the transonic velocity range again?
 

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Personally, I just love rifles! More specifically, I really like rifles for big game hunting. Not unlike many others here, I happen to own a bunch of rifles in a bunch of different calibers/cartridges. Several dozen rifles in somewhere over 30 different chanberings, or thereabouts. All that nonsense being said, I'll also admit that after having harvested big game (mainly deer) with 20+ different chamberings, I'd also have to admit that IMHO there's not a whole lot of difference when using a rifle for hunting at typical harvest maximum range (let's call that 250-300yds) between shooting something with a 6.5x55 or 7x57 and shooting something with a .300 Win mag or .350 Rem mag, so long as you shoot 'em in the right place.

It might be interesting to watch shooters argue the merits of the 7mm mag over the 30/06 (or the .270Win over a .308Win, for that matter) as an example, but I doubt one could hang a turkey's tail feather off the actual differences, one to the other. It makes for interesting banter, perhaps, but you cannot convince me any of it's truly remarkable stuff, when you have an experienced shot shooting any of them at a typical game animal. Yup, I like lots of different guns and do use a good number of them, but I certainly don't worry most times if my hand closes around a Ruger #1 in 7x57, a CZ550 FS in 6.5x55 or a Rem 673 in .350RM, because they will all do the job, if I do mine.
 

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It will be less confusing if you think rifle/cartridge/game as opposed to 'the book says this about the 7RM' and 'the book says that about the 30-06' and soon you think all these numbers are so close there shouldn't be anything but 30-06s on the planet. Now if you hunt bear in the North Maine woods you will soon learn to take your 20" barreled 30-06 loaded with heavy Noslers and if you hunt deer over a South Carolina beanfield you will take your 26" barreled 7RM loaded with ballistic tipped boat-tails. But if you have to choose one rifle/cartridge for all the game in all the country, then you will come up short at some point. You will also overkill too, but that isn't really quite as big a problem, if it is a problem at all. The solution is to buy many different rifles for all the different game.
 

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Discussion Starter #14 (Edited)
It will be less confusing if you think rifle/cartridge/game as opposed to 'the book says this about the 7RM' and 'the book says that about the 30-06' and soon you think all these numbers are so close there shouldn't be anything but 30-06s on the planet. Now if you hunt bear in the North Maine woods you will soon learn to take your 20" barreled 30-06 loaded with heavy Noslers and if you hunt deer over a South Carolina beanfield you will take your 26" barreled 7RM loaded with ballistic tipped boat-tails. But if you have to choose one rifle/cartridge for all the game in all the country, then you will come up short at some point. You will also overkill too, but that isn't really quite as big a problem, if it is a problem at all. The solution is to buy many different rifles for all the different game.
Well actually, I am looking at this with the thought of rifle/cartridge/game. Because if what Im looking at is correct, then the 7mm Magnum has no real bean-field advantage over a .30-06 when taking a buck at extended ranges.

So long as the shooter is competent, and keeps an intimate familiarity with the trajectory of his cartridge at the time.
 

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Discussion Starter #15
"And what is the transonic velocity range again?"

Speed of sound is around 1,150 fps, depending on altitude and humidity.
Well, the .30-06 does actually maintain that standard out past 1000 yards or so. Depending of course on altitude and air density, as you stated.
 

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Discussion Starter #16
I find myself taken back by the realization, that we are talking about Magnums here. We're not comparing '06 with .270...we're comparing it with magnums. We are comparing cartridges that are not even similar. Not in composition, construction, or even reputation.

The magnums are supposed to be the venerable speed-demons, noted for flat shooting, long-range accuracy. And so far, when we reduce the bore size, the performance differences become almost indistinguishable, for any given bullet weight.

Fascinating.
 

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Well, in all fairness, how could you expect a 270 Winchester and '06 to be all that different, when shooting bullets of the same weight? They are using the same case, with the same capacity. :)

You are seeing the differences as nominal, which they are. However, like a beautiful woman, or a stout ale, the differences are very important to the astute observer! Does 3" less drop at 400 yards matter to you? Well, if the antelope buck of a lifetime is missed or only wounded, because of it, then it certainly should. When it comes to bottle-necked rifle cartridges of recent vintage, (last 110 years, or so) they are similar, but that is not to say their differences are of no consequence. There is good, there is better, and then there is excellent! For some people, good is "good enough". For others, nothing less than the very best will do. Nothing wrong with either school of thought; just be wise enough to know that the differences are real, even if they are also slight. ;)
 

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My only experience is with .270 and 7mm WSMs and a .257 Weatherby and bullets that were too fragile. I have seen some ridiculous holes and splash wounds inflicted by a few friends of mine with the .257 and .270 Mags. And I did it once myself with a 7mm WSM and cheap 150 soft points. I mean LUDICROUS holes. And some lost game with those buddies' .257 Weatherby and .270 WSM. Seen it with a .25-06 (another overbore round) a couple times too. I think the .270 and 7mm Mags are fine, BUT.....use a premium bonded bullet and use one on the heavier end of what is available (150gr for the .270 and 160gr for the 7mm). Trophy Bonded are my favorite. I have never heard anything negative about A-frames either. I have not yet tried Accu-bonds, but I bet they are good medicine too. If you ever have to choose between a .30-06 and one of these flat shooting overbore magnums with both using standard bullets, go with the .30-06! It works EVERYTIME, and does it without blowing holes that look like BP's well in the gulf!
 

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Well, in all fairness, how could you expect a 270 Winchester and '06 to be all that different, when shooting bullets of the same weight? They are using the same case, with the same capacity. :)

You are seeing the differences as nominal, which they are. However, like a beautiful woman, or a stout ale, the differences are very important to the astute observer! Does 3" less drop at 400 yards matter to you? Well, if the antelope buck of a lifetime is missed or only wounded, because of it, then it certainly should. When it comes to bottle-necked rifle cartridges of recent vintage, (last 110 years, or so) they are similar, but that is not to say their differences are of no consequence. There is good, there is better, and then there is excellent! For some people, good is "good enough". For others, nothing less than the very best will do. Nothing wrong with either school of thought; just be wise enough to know that the differences are real, even if they are also slight. ;)
But, the trajectories of the '06 and 7mm Magnum hardly differ much more than an inch, or sometimes less, at 400 yards.

Besides, a successful killing shot to an animal is based on one's mastery of his own chartridges trajectory, not the properties of the trajectory itself. Flatter shooting, does not always mean, more accurate. Especially if the differences in drop are so marginal.
 

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Discussion Starter #20
You and I are getting different stats. In round numbers, I'm seeing a 140 grain 7RM bullet leaving the barrel at 3200 fps getting to the 400 yard mark 200 fps faster, hitting 4.5" higher, with 100 ft/lbs more energy and getting there .28 seconds quicker than a 150 grain .308 bullet starting out at 3000 fps from an '06. That's what the book tells me.

Books are only guides and like they say, your mileage may vary. I shoot at deer sized targets pinned up at 400 yards. What I see is more holes in the vitals when I use a 26" barreled 7RM than the old '06. Maybe it's because of less hang-time with the lighter, faster bullet, or maybe I just feel good about shooting the 7RM when the deer is farther out.
Well of course, if youre using two different bullet weights. But the context of this discussion is with regards to using same bullet weights. Well, same as possible.

Your figures above are certainly proportionally accurate. But I would say change your 7mm bullet weight to the 154gr, which is closer to 150gr (unless you know of a 150gr 7mm bullet). Once this is done you should see the velocity come down closer to 3000 fps, and both bullet trajectories should come closer to evening out.

To compare field experience, at 400 yards, Im shooting a 168gr @ about 2850 fps, and averaging about 3.5 to 4 inch groupings. Im quite certain I could do the same with your proposed 150 gr load listd above. Our difference in rifles may be the determing factor.
 
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