e=mc^2

Whenever I hear someone talking about bullets, somewhere in the conversation those numbers on the bullet box comes up. You know, the (number) x (number). Every time I see or hear it, the first thought that pops into my head is "e=mc^2": no idea what they mean, might as well be a foreign language (or physics, see above). So I was hoping someone in this group could explain the numbers to me?

Nice to see a post in this group. Do you mean something like "7.62x51?" The first number indicates the diameter of the bullet, in millimeters. The second indicates the length, also in millimeters.

The 7.62x51mm round (also known as the "seven six two NATO") is dimensionally identical to the commercial cartridge known as the .308 Winchester, which is measured on the inch scale, in decimals. The pressure is often greater in the NATO load, though, compared to the commercial load.

The military and most of the rest of the world use these metric designations, while the U.S commercial market generally measures by decimals of the inch.

Ah, thankee. Those were the numbers I was referring to. My knowledge of guns can be summed up with "They're fun. Get ear plugs."

Just a little clarification here, in a 7.62x51 the 51 is the length of the CASE in mm, without the bullet.
Also, you might run across 7.62x54 R, the R tells us that the case has a rim on the base. Just a little more info to confuse you.
Bob

I was reading 'AMERICAN RIFLE: A Biography by Alexander Rose. It is interesting, especially if one wants to know how the rifle industry progressed and how military doctrine interacted with commercial manufacturers to retard the progress of more effective weapons. There is nothing more true than the expression that 'We are always preparing to win the last war the next time'. It also illustrates my observation that progress can only occur when the 'Old F--ts' retire. It is natural that we become accustomed to certain types of equipment in our youth, and then continue to prefer them all through our lives.
I remember reading in 'BLACK HAWK DOWN' about how our small rounds went through the Somalis, but would not disable them. This is probably why everyone else prefers the AK-47. When hit by one of those bullets, it's hard to ignore the wound.

This is probably why everyone else prefers the AK-47.

Last year, I read Lone Survivor and Bravo Two Zero, and both of the elite soldiers who authored these books seemed (if I remember right) to be downright disdainful of the AK-47, which has poor, primitive sights and isn't very accurate in the first place. I think a lot of soldiers would agree that the 5.56 NATO round leaves something the be desired when it comes to stopping power, but it is generally thought to more destructive at moderate ranges than the old 7.62x39 AK-47 cartridge, which has been superseded by the 5.45x39mm (a cartridge similar to 5.56 NATO) in the AK-74.