.30 cal rifle accuracy

I was reading stories of the history of the National Matches, and read about some of the rifle matches. Apparently the M-1 Garand rifles firing the 30-06 round were replaced with .308 because the .308's were just more accurate. I was under the impression that the bullets are the same whether in a .308 or a 30-06, and you should be able to chrono the ammo to the same velocity, so why is there a difference?

If you reload, the bullets are the same. If you use standard ammo, the .308s had a boat tail. The .30-06 had a flat base.

The .308s recoil less. It's easier to hit the center if the gun isn't pushing you off target as much in recoil during the rapid strings. Even in the slows, you don't have to work as hard to rebuild your position if it doesn't degrade due to recoil.

The main reason the 30-06 replaced the 308 was the military switch from the Garand to the M14.

gulliver62 wrote:The main reason the 30-06 replaced the 308 was the military switch from the Garand to the M14.

NATO adopted the 7.62x51. After that, we fielded trials in which the M14 was selected as the winner.

http://guns.wikia.com/wiki/7.62x51mm_NATO

Rob Kovach wrote:I was reading stories of the history of the National Matches, and read about some of the rifle matches. Apparently the M-1 Garand rifles firing the 30-06 round were replaced with .308 because the .308's were just more accurate. I was under the impression that the bullets are the same whether in a .308 or a 30-06, and you should be able to chrono the ammo to the same velocity, so why is there a difference?

Just because the bullet diameter is the same doesn't mean that all rifles of that caliber will have the same accuracy. A 22 Hornet is not as accurate as a .222, a .244 or 6mm Remington is not as accurate as a 6mmPPC. Rifles are a completely different animal than pistols. The degree of taper of the case walls can affect accuracy as well as the shoulder angle. Also the .308 is a short action cartridge and the .30-06 is a long action cartridge. All these thing affect and change the way the powder burns and efficiency which affects accuracy. Also barrel twist rates can be different. There is a rather large list of things that can affect rifle accuracy that really doesn't come to play in the pistol world.
Scott

Creighton Audette, a gunsmith, machinist, metallurgist of some note in the match rifle world told me once that the .308 was "inheritantly more accurate" than the .30-06 because of the powder to case ratio. He said that more close to full the case is with powder and still keeping within the pressure parameters, the more "inherently accurate" the caliber was. He said it was the main reason it was much harder to get the .30-06 to shoot well, by comparison.
Scott
Vermont