How does the 30-06 range in size of caliburbetween 270, 30-30, 30-06, and the .300? what i'm asking is please put them in scale from least to greatest power. also, what the heck kinda shell do you use in the 7x57 or any of the other x calibers? what designation do they have and where do you find ammo for them?

The 30-06, 30-30, 308 and all of the 300 Mags are .308 caliber. The 270 is a .277 caliber. The 7MM Mag, 7X57, 280 and 7mm-08 are all .284 caliber. The difference in these cartridges is the size of the brass casing and the amount of powder they hold. Walmart and most good sporting goods stores sell ammo for most all of these. UIf you really want to learn, pick up the book, Cartridges of the World or a good reloading Manual like the Hornady set. The 6MM and 243 are .243 caliber. Most all the 22's are .224 caliber.

30-30,7x57, 270 30/06 and .300(if it's a magnum)

The easiest way is to browse some ammo manufacturers sights, like remington, winchester and Hornady. They all list speeds, energy figures and trajectories of the various shells and calibers. This is a good way to compare them as to performance.

Some will over lap depending on how they are loaded.

For the ones you listed as far as power goes I would rate them like this.

30-30 least powerful, good deep brush caliber though at shorter distances. lOT's of deer have been taken with this caliber in the midwest would be my guess.

30-06 and 270 are pretty close in my opinion with the edge going to the 270 for deer. Depending on the loads you use I think the 270 shoots a bit flatter and tends to be a fairly accurate caliber. I believe the 30-06 has a bit more power down range though. I would have to look them up to compare them, and I didn't. That is something you can do on your own. Both are extremely popular rounds and you can find ammo for them anywhere. The 30-06 is considered a DO ALL cartridge and one of the most popular loadings in history would be my guess.

The 300 win mag (I assume that is what you are talking about) is the most powerful of the bunch. It has more range and more power down range with the flatest trajectory. The down side is it is most likely expensive to shoot, has more recoil and would do a fair amount of damage to deer sized game. This is more of a long range weapon, or large game weapon, like moose or something like that. My opinion anyway.

And there are a ton of calibers you left out that fall in between there. Like the .308 and 7mm mag. Or 25-06 and .243.

Paul

To echo what ridgerunner said, the metric calibers use the designation of bullet diameter by shell length, just as a 2x4 is known as a 2 by 4 in the lumber business.