I know they’ve made dozens of different calibers over more than a century. But what would be, say, the ten or twelve most common calibers produced today? (I’ll count incompatible cartridges with the same bullet diameter as two different calibers.)
Since the US uses .223 for the M16, and AK47s use .308 (as do M60s and HK-91s, etc.), these two calibers must account for some large percentage of all the ammunition produced every year.
.223/5.56 NATO
.308/7.62 NATO
7.62x39
.30-06
.270 Winchester
5.45x39
.22LR
.243 Winchester
7mm Magnum
.300 Win Mag
.45-70
.30-30
These are in no particular order, though the military cartridges at the top certainly will be among the most produced, though by sheer numbers, .22lr is probably number 1 since it’s so cheap.
I also have no cite other than seeing what’s usually in stock at most stores.
Finally, I am aware there are some differences between the NATO rounds and their civilian counterparts, so that some rifles will only shoot one or the other, but I’d still group them together.
I’d say that in civilian hands anyway, the most common caliber is .22 Rim-fire. And most likely for total rounds fired as well.
The AK-47, etc use 7.62x39, which is a different cartridge than the .308/7.62 NATO.
7.62 by 39 may be .308 in diameter but .308 normally refers to .308 Winchester or 7.62x51mm NATO. In the same way, .22 generally does not refer to .223.
The OP specifically asked for caliber, not cartridge size.
I own an HK-91, so I’m well aware of the difference.
I am assuming the OP wasn’t actually asking about caliber, but simply different cartridges, since he mentioned them in his post. If the OP wanted caliber only, then you are correct.
I used to reload for my Mini-30, and if I recall correctly, the die had two interchangeable mandrels or swages or whatever they are called that would open the mouth up to accept either a .308 or a .311 caliber bullet, the latter better suited for Russian weapons like the SKS and its clones.
I have done an Online Pole in a gun forum when I set up a Power Point “Family Feud” game for my firearms safety students.
This was then for the "Most Popular Deer Cartridge/Gun.
- 30- '06 Springfield
- 30-30 Winchester(30WCF)
- .270 Winchester
- 12 Gauge w/slug
- .308 Winchester
Those were the most common and were used in the game. The Firearms safety class(11 & 12 year molds only missed the .270 a couple weeks back.(this was the 1st night) I like to access the overall knowledge of the class early on.
Other close entry’s were,
7mm Remington Magnum
.243 Winchester
25-06 Remington
7mm-08 Remington
300 Savage
again this reflects Deer Hunting only.
Did you mention that there are more deer poached every year using .22LR than are legally taken with any other cartridge? 
In one of Jeff Cooper’s books he opined that there are way too many calibers. He said we could easily get by with just half-a-dozen calibers (total) for rifle *and *handgun. I would agree.
Where’s the fun in that? If there were only 6 calibers, we couldn’t argue for eons over which was best in what situation. Come on, dude! get with the program!
**
silenus** - who owns more than a half-dozen calibers just in Mausers alone.
Probably true, except the debate over which half-dozen has led to endless variation. 
Or more relevant, where’s the profit in that?
Arms manufacturers make much of their money from making & selling ammunition, or licensing others to do so for their guns. If they used a standard cartridge, people could buy them from the cheapest supplier, rather than their brand name ones.
Just like ink cartridges for inkjet printers – we could easily get by (and customers would save money & irritation) with just a dozen or so types. But every printer company tries to introduce new, patented/restricted cartridges for each new printer.
LOL.
I belong to a number of gun-related message boards. Every few months a newbie will start a thread entitled, “What should I carry: 9 mm or 45 ACP?” I will *never *participate in a thread like that. Another is, “Which is better: .223 or .308?”
Threads like that go on for a *nauseating *20 pages. I’ve learned my lesson… I don’t even click on those threads.
I don’t see the problem.
It’s the .40 S&W.
d&r
.25 ACP. The pumice stone in the rock pile of the gun world.
No, the .40 S&W is definitely underpowered compared to the 10mm or .41 Magnum. <JK!>
I’d never use a .22 for deer hunting. There’s too much risk it’ll run off and die in the brush.
I’ve always hunted with a .30-30. I try my best to find any deer that gets into the brush. My family eats what I hunt. Killing an animal and wasting it would bother me.
You could be right about poachers. I let the fish and game officers take care of them.