[in the Arena]

>>Not sure what the 7.62 X 54 is

Ok, the following is not meant to be an end-all definition, just basic info:

7.62 X 54 is the Commie equivalent to our 30'06...sort of, but I believe it's a rimmed case.

7.62 x 39 is the AK/SKS round.

7.62 x 51 is the NATO round (commonly referred to as .308)

So, ignoring my simplistic response click the following:

7.62 mm caliber

Scroll down to: "Military cartridges in 7.62 mm calibre "

Good luck,

Jim

[Hazcat]

OK I think I've got it.

762x51 NATO = .308

726x39 = AK or SKS type

762x54 = Mosin Nagant or Dragunov (I have also seen 762x54R but I'm not sure this is the same round).