[hoppinglark]

What is the true caliber of .30 Carbine?
What is the true caliber of .30-06?
(as in a .38 special is really a .357 or .358 bullet)
I'm just wondering because a .30 carbine is much bigger....

[Mike Irwin]

Bullets for .30-06 and .30 carbine measure nominally .308 inches in diameter. There can be some variation among manufacturers.

A .38 Spl. uses a bullet .357 in diameter, again nominally.

[Sunray]

"...I'm just wondering because a .30 carbine is much bigger..." Than what?

[hoppinglark]

guess i was really off the mark...I though the .30 carbine used the same brass as a .30-06 but not crimped down...sort of like a 5.56 and a 9mm
same extractor different upper.. guess i was wrong

[David4516]

Nope, the .30 Carbine case is much smaller than that of the .30-06

http://www.marstar.ca/ammo/images/30-M1-Carbine.jpg

But the bullet diameter is the same for both rounds (0.308)

[Art Eatman]

hoppinglark, for comparative performance: The GI Carbine's cartridge sends a 110-grain bullet out at some 2,100 ft/sec. The '06 sends a 150-grain bullet out at 2,700 (military loading) to 3,000 ft/sec (handloads).

The volume--powder capacity--of the '06 brass is about 2.5 times that of the Carbine.

Art