Based on that, you've then got to consider under what circumstances you'd need the weapon - and what your resupply source would be. If you're talking worse-case scenario, then you're talking an invading force (whether foreign or domestic). Domestic forces will have the 5.56, foreign would either have 5.56 or 7.62. Ideally, you should have one of each - this way, you're covering your "bets". For sidearm - well, you're talkin' 9mm for domestic, unless you're dealing with certain specialized troops that tote the .45 still. Foreign - I'd have to dig before answering THAT one. Flip side of that is that if it got THAT bad, I figger I can always pick one up in the field, as it were.
Having said that....most military groups teach familiarization with both "house" and "foreign" weapons, simply because you never know which one may come to hand in a SHTF scenario. That's why I CARRY a .45 - but OWN many other calibers and styles.
Having said that....most military groups teach familiarization with both "house" and "foreign" weapons, simply because you never know which one may come to hand in a SHTF scenario. That's why I CARRY a .45 - but OWN many other calibers and styles.