Ammo Survey: Gun Owners on Calibers And What Makes Them Popular - The Truth About Guns

Handgun
.38
_It's reasonably priced
_Cartridges are easily reloaded (but most center fire cartridges are)
_I find a .38 speed loader easy to handle yet small enough that I can easily carry 2 or 3 regardless of what I'm wearing (That's right I don't wear a speedo swimsuit)
_.38(p) put down injured or harvested livestock without a horrendous mess (I use a captive bolt stun gun if it's safe to hold the animal
_ My .38 revolver is a nice size for concealed carry, and if necessary will still poke a respectable hole in someone intent on hurting me and mine.


Rifle
Depends on what I'm doing.

If adopted by the government e.g. 7.62 mm NATO, 5.56 NATO, 9 mm, .45 ACP, and even the .50 BMG round, it's a big step up in popularity (lots of civilian contractors making that ammo) and a lot of re-loadable brass available to supplement the commercial availability of that round, it can't help but find favor with the civilian shooters as well.
It is also an endorsement (though from a sometimes untrustworthy source, government) of the good qualities to be found in those rounds.

Interesting article. I have not even heard of some of those rounds.