As mentioned, get "Cartridges of the World" or if you can't wait more than a day, a reloading handbook from a gun store or gun show, but generally, the actual calibers/diameters of the most popular cartridges are as follows:
1) .17 (or is it .177?)
2) .224 ("22 cal")
3) .243/6mm
4) .257 ("25 cal")
5) .264/6.5mm
6) .277 ("270" sometimes)
7) .284/7mm ("7mm" or "280")
8) .308/7.62mm ("30 cal")
9) .323/8mm
10) .338 ("340" sometimes)
Hmmmm
11) .358?
12) .375
13) .416
14) .458
then some rarer ones, like Nitros or BMG
15) .477
16) .500
and even bigger up to .700, I think.
and possibly a few others in between also, like .311/.312. These are just the diameters. There are several to many cartridges with each diameter, esp. 22, 7mm, and 30. I recommend Lyman's 47th Reloading manual for good all-around manual. A rough guess of the popularity of particular diameters might go like this, using the numbers assigned above, from most to least popular (based on # of rifles owned/sold, not just on # of cartridges in a caliber): 8, 7, 2, 4, 3, 6, 10, 5, 9, 12,
[This message has been edited by Futo Inu (edited January 13, 2000).]