Why 308?

[Interloper]

7.62x51mm NATO was designed to be a direct replacement for .30-'06. For mid range bullet weights it duplicates '06 ballistics perfectly. The over all length is shorter, making it more practical for automatic weapons. That's really all there is to it.
From a sportsman's perspective the '06 has an edge. greater case capacity equals better velocity with heavier bullets, say 200 grain and up.
Although .308 WIN and 7.62 NATO have a few differences, SAAMI specs the two as interchangeable. At least in commercial guns.

[xrMike]

Another reason to switch, not mentioned yet:

.308 is inherently more accurate than ought-six.

[Interloper]

Another reason to switch, not mentioned yet:

.308 is inherently more accurate than ought-six.

Old wives tale.

[elSquid]

The military did have a rifle chambered in 30-06... its called the GARAND. There was even s "Sniper" version but it suffered from being a poor mounting platform for optics.

As another data point, the Marines also used Winchester model 70s in 30-06 for sniping during Vietnam; Carlos Hathcock is probably the most famous user of said rifle.

-- Michael

[xrMike]

Old wives tale.

No, I'm pretty sure it's true. Here's some info to chew on:

http://yarchive.net/gun/rifle/30-06_vs_308.html

http://yarchive.net/gun/ammo/308_vs_30-06.html

http://snipercountry.com/Articles/AccuracyFacts.asp

[smle-man]

Generally speaking a shorter cartridge case has more accuracy potential than a longer one.

[ETD1010]

Although .308 WIN and 7.62 NATO have a few differences, SAAMI specs the two as interchangeable. At least in commercial guns.

Careful. I know most commercial rifles are .308 chambers, but if you stick a .308 into a 7.62x51 chamber you can hurt things, as the .308 had a bit more pressure.

[Tanner68]

With the same weight bullet, say 150 to 180 grains, the 308 edges out the 30/06 in accurarcy because of the smaller case volume. With modern powders, the 30/06 has a lot of loose powder in the case that can make for less consistent burns or ignition. But that increased case volume can help sportsman when loading up to 200 and 220 grain bullets, which the 308 can't handle because of insufficient case volume.

But I am just a keyboard commando, with limited reloading experience.

[Interloper]

So why exactly does a case with less capacity have more accuracy potential? Depending on your powder, you can fill an '06 case to compression capacity and stay within factory pressures. Naw, I don't buy it.

[KillZone45]

yup nato was already using the fal

besides 30 06 was kind of overkill

So now they are using the 300WM, 338LM, some caliber of the Chey-Tac, 50cal, etc. Aren't those overkill? Or were you referring to back in the day, Vietnam era when the 308 was being used?

[1911ZENSHOOTER]

why not?

[xrMike]

So why exactly does a case with less capacity have more accuracy potential?

It's not total case capacity that matters so much as "aspect ratio" (or whatever you call the relationship between case length and width; in airplanes, when talking about wings, that relationship is called "aspect ratio"; I don't know what you call it for bullets, but that's what I mean... ).

Like somebody said previously, a short squat powder charge (for whatever reasons I don't pretend to understand) drives a bullet more uniformly than long thin charge.

The historical change in average group sizes at shooting competitions seems to prove this.

I doubt the military knew about this when they made the switch from .308 to -06. It was just a lucky, unforseen result I'm sure.

[BigRich]

Shorter actions are also usually slightly stiffer and this adds a little more accuracy.

[Napalm Bulldog]

Why .308? Because it works!

[MissionMTMan]

So now they are using the 300WM, 338LM, some caliber of the Chey-Tac, 50cal, etc. Aren't those overkill? Or were you referring to back in the day, Vietnam era when the 308 was being used?

There is no such thing as overkill. We shoot to kill so what's the difference between a dead man with a little hole and a dead man with a huge hole? The hole size? Come on now. Killing is Killing. If I had to die by a bullet, I would want to be shot by the larger caliber because I would die faster. Die faster=more humane for the bleeding hearts out there. Okay, rant over.