.30-06 vs. Small-bore Magnums???

[~Trigger~]

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.

Well 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 the magnums?

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

[Unclenick]

Depends on a number of choices. If you look only at velocity, then the milder, older magnums, like 300 H&H may add only 200 fps to the .30-06 for a given bullet weight, but the others of middling age, like the .300 Win Mag will add 300 fps, and the .300 RUM and .30-338 will run 600 fps faster.

Since energy goes up as the square of velocity, the big ones carry 50% more energy. But that's not always the criterion.

For example, in long range shooting the extra powder in the magnum lets you shoot a heavier, higher ballistic coefficient bullet fast enough to remain above the transonic range all the way to 1000 yards. The '06 has to use a lighter, lower bc bullet to do that. The result is, the .300 Win Mag can easily cut a third off the wind drift the '06 will give you at that long range.

So, it depends what you are trying to get done?

[~Trigger~]

Agreed, I fully acknowledge the performance increase that nearly all .30 caliber magnums have over the .30-06.

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.

[~Trigger~]

It should be noted, that these comparisons negate the "Ultra" Magnums as clearly those outperfrom. So we are just discussing the "Normal" magnums. If that makes any sense.

[GeauxTide]

I've chrony'd alot of '06 and 7mmRM loads in equal length barrels (24") in five different rifles. With 150gr bullets, accuracy in the 30-06 falls off after 2950. The 7mm shoots more accurately with heavy loads. This is primarily due to the expansion ratio (bore vs. capacity) of the cartridges. Yes, I can get over 3150 in the 7mm, but it takes almost 20gr more powder. To 300 yards, there is no practical difference between the two. Also, after loading 270 and 280, they behave the same. Most of the time, the medium cases like the medium powders at about 80-85 case full. Accuracy? Best I've obtained in 3 7mm rifles is 1 3/8". Best in the 280 and 30-06 is 7/8".

[Brian Pfleuger]

One thing to keep in mind is that the smaller caliber guns 7mm, 6.5, 6, will most often not be shooting those same bullet weights as the 30 cal.

Could they? Yes, but most often they are not. In fact, they may often have trouble stabilizing the heavier bullet and those loads may not even be appropriate for the majority of guns chambered in that cartridge.

For example, while they're not "magnums", 7mm-08 loads will often be listed as high as 175gr and many sources show loads in 204 up to 55gr. Most 7mm-08 guns and most 204 gun will not stabilize those bullets.

So, back on your question, the advantage of those cartridges comes in bullet weights that are lighter than the bullets that would be used in the larger calibers. Lower weight, more speed, flatter trajectory, less recoil. (All generally speaking)

[csmsss]

It's all about sectional density. For two bullets of equivalent weight, construction and contour, the bullet with the narrowest diameter will have the better sectional density and will have proportionally better momentum and downrange velocity as the range from the muzzle increases.

[woods]

It's all about sectional density. For two bullets of equivalent weight, construction and contour, the bullet with the narrowest diameter will have the better sectional density and will have proportionally better momentum and downrange velocity as the range from the muzzle increases.

x2

and sectional density is an indication of penetration potential, all other things being equal. IOW, a 140 gr bullet out of a 264 win mag with a sectional density of .287 will penetrate further than a 165 gr bullet out of a 30-06 with a sectional density of .248, velocity at impact and bullet construction being the same. Add the velocity of the smaller caliber magnums and that will extend your effective range. But sectional density changes as soon as the bullet starts to expand and will continue to change as the bullet penetrates and the frontal diameter changes.

But there are so many variables that terminal results often vary.

[sc928porsche]

200 fps is a lot!

[wncchester]

Trigger, what you're seeing is that within "normal" hunting distances, inside maybe 300 yards, neither velocity nor high bullet BC makes a lot of difference. The -06 is so good hunters have to go to some significant extremes before any "magnum" makes a difference...and then it's not massive!

I listen to all the campfire BS about what great killers magunums are and smile, nodding my head. But I still use my .35 Rem/336 in dense woods, my .243/Vangard after the leaves start to fall and my -06/700 when the leaves are gone. No deer has ever noticed any difference nor have I ever felt under-gunned!

An extra 200 fps is a lot...on paper. Well, a little anyway.

[Slamfire]

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

1. Create Revenue flow

2. To increase the chance of wounding and loosing game at long distance by people whose marksmanship skills are so poor that they can’t hit a barn while inside it.

According to this, you don’t have to hit a vital spot at all.