Define 7mm. Do you mean 7mm Mauser ( a little less than 30-06), or 7mm Magnum, (a bit more than 30-06)
7mm generates more pressure.
The 7mm Remingtonn is longer. The 30/06 has a larger projectile.
There are several 7mm cartridges out there.. the basic 7x57 will have less recoil than the .30-06, but there are cartridges marketed as 7mm which produce significantly more recoil.
The 30-06 shoots a bullet which is 7.62 mm in diameter, so the 30-06 is "bigger" in that sense. Several different weights of bullet are available in either caliber, so that's an undetermined variable. There are several different 7mm cartridges (7mm Mauser, 7mm Magnum, 7mm H&H, 7mm-08), so you have to be more specific when comparing ballistics.
Muzzle velocity and muzzle energy. 7mm uses .284 diameter bullets and the .270 uses .277 diameter bullets. The .270 is basically a necked down .30-06 case. 7mm comes in several different flavors. The 7mm Mauser is 6mm shorter than the .270/.30-06 and has less powder capacity. the 7mm Remington express (.280 Rem) has the same length (very close) as the .30-06, but the shoulder is slightly farther forward. This prevents it from being accidentally chambered in a .270 or .30-06 and gives a bit more powder capacity.
NO, doubt it would even seat completely in. The base of the 7mm magnum (case before neck) is longer then a 30-06.
7mm, yo.
The 30-06 ( say thirty ought six) fires a bullet that is 7.62 mm in diameter. The 7mm fires a bullet this is, well...... 7mm. 30-06 has a bigger bullet. The size of the GUN can- and does- vary. BTW- catridges such as the 7mm MAGNUM will have greater energy than a 30-06. So- what is your definition of bigger?
30/06 is one
Do you mean the length of the cartridge or the diameter of the projectile?
Which 7mm (there are several), and for what purpose? Each has strengths and weakenesses over the other. You have to weigh and measure them and figure out what works for you.