I suppose I'll chime in here. I have expereince with all of the rilfes and ammo mentioned, in the USAF.
The 5.56 round is a good round, if lightweight for human targets. Personally, I don't subscribe to the "lighter, faster" theory, but it's OK. For range work, it's great - the recoil is almost nothing, and AR's can be made very accurate these days. You MUST choose your ammo and rate-of-twist for your rifle very carefully, though - so that they're matched well, for best performance. Also, the AR series has a MAJOR design flaw: the gas system. Direct gas impingement is not a good way to operate a firearm. It's VERY dirty, throwing carbon and unburned powder & small metal fouling particles into the action, which needs to be as clean as possible for reliability. Everyone who owns an AR can attest to this: it is a B*TCH to clean out all of the carbon fouling from the gas system, and especially the bolt & bolt carrier. Also, the flimsy gas tube sucks - it's a major source of malfunctions and jams. A little redesigning would go a long way here, and it's already been done in Stoner's later designs, but it'll never happen.
Personally, I LOVE the M1 Garand/M1 (M14) rifles. Having said that though, I don't feel it's the best choice for actual COMBAT use anymore. The .30 M2 (.30-06) round tends to overpenetrate on humans, at modern battlefield ranges. The .308 is better, but it's recoil wants a heavier rifle than the AR's - like the M1/M1A/M14. However, anyone who's had to hump one of these, along with the heavier ammo (and less rounds for the same weight), will tell you that they'd rather have something lighter! Also, as I'm sure you've heard, the M14 is impossible to control in full auto (unless you're talented AND highly trained), which is virtually required in combat now. The round is just TOO powerful for the weight of the weapon, and the designs of the muzzle breaks/compensators. Clearly, something in-between is needed.
The 7.62x39 round is OK, but as some have said, it has less range than the 5.56 NATO. Still, it hurt like hell when I got a 7.62x39 bullet in my leg (ricochet)! While the Soviets did a decent job with this round, there are better alternatives out there now. The same can be said about the "downsized" Soviet round, the 5.45x39. I feel that the Sovs cranked the size down a little TOO much for this one. This round was a hurried attempt to compete with the US and NATO's switch to the 5.56, while keeping as much of the tooling and parts of the AK series as possible (hence, the same 39mm length and case head size). Now, the Sovs did a darn good job on the bullets - the fragmentation and tumbling effects destroy tissue pretty darn good - ask the Afghans about that! - but the accuracy just isn't there.
I personally believe that what is needed is a complete RETHINKING of military small arms. They need to start from SCRATCH with a clean sheet - no "reusing" of anything; ammo, parts, accessories, nothing. Since the US Military is going to transition to several new weapons/ammo types soon (the new H&K designed "system" whose designation escapes me right now, and the new "green" frangible ammo, and also the proposed plastic-cased ammo), now would be a good time to start the research, even though they should've started it a lot sooner. They need to do extensive testing on what exactly is the best all-around compromise between range, wounding capability, accuracy, weight, reliability, and recoil. This means finding the right caliber, construction, & shape of bullet, size of the case & its material, and THEN design a weapon around it, after they've done the research on the ammo (optimal rate of twist, barrel length, etc). The British did research similar to this back in the 50's, I believe. They determined, if memory serves, that a .26 caliber bullet is the best compromise between wounding effects, power, range, recoil, and individual soldier's carrying capacity - still carrying as much ammo as possible, however. I'd like the US Military to do the same thing - but this time, actually implement the research. They could start over, or continue from where the Brits left off, I don't care. But our troops would finally have the BEST weapons in the world, which they certainly deserve. The AR series just isn't good enough anymore - and they're doing what the Russians did for years: make the basic design last as long as possible, so they don't have to design an all-new weapon. That just isn't a good way to ensure people have the best available weapons anymore.
If you're looking for a rifle for your own personal use - at the range, for hunting, or for SHTF "scenarios", I'll give you a couple of recommendations. Personally, I like the G3/CETME rifles. They're in .308, but aren't nearly as heavy as a M1A. They're easy to work on, are great shooters, and accurate. The recoil is very manageable for semi-auto .308's. Ammo's plentiful, and cheap - and it'll be around for SHTF. The CETME's are ALMOST the same as the G3 - a few things like sights, are a bit different - but the important thing is, the mags are interchangeable between them. G3 surplus mags are very plentiful, and cheap - I see them all of the time for $3 each!
AK's are VERY reliable, and ammo's plentiful. For SHTF in the US, however, ammo may not be around (unless we're invaded by a country that equips their military with AK-types - unlikely). They're inexpensive, parts are plentiful, and easy to work on. Caliber is a toss-up: do your own research, and get whatever's more comfortable to you.
I personally would stay away from an AR. I love the looks of them, and I do plan to buy another one for my collection, but I'd get something else first, for the reasons already mentioned. If you must have a 5.56 rifle, I'd go with an AK in that caliber, or a HK variant - even though they're pricey. The reliability factor is worth the extra cost, in my opinion, and I'm a notorious tightwad!
The FAL is also a good choice, but they're heavier than the G3/CETME, and more expensive these days (the upper recievers cost the same as an entire CETME rifle, plus accessories!). The FAL is very popular, and parts are all over the world, but I feel that there are better rifles out there that are less expensive, just as reliable, and chambered for the same .308 round. Buy one if you must, but I'd look elsewhere.
If you can find one (and afford it), an AN-94 from Russia is a wonderful rifle. The Russians also have a plethora of great, advanced rifles that they've designed and built in the last decade, but they're scarce - especially in the US, as Class III firearms can't be imported (except for military/LE use). Another firearm I really, REALLY like (but I'll never own due to restrictions) is the P-90, from FN. It's technically a "PDW", or a sub-machinegun. But, I'd take one in a heartbeat if I could get my hands on one, even to the point of selling my car to pay for it! But that's me, and it's also wishful hoping...
If I can be of further assistance, I'll be glad to help. I have extensive experience with military small arms (shooting, maintaining, and fighting against most of them), and if I can't answer your question, I'll certainly try to find someone who can.
on a pic of Bin Laden with one. But I would rather have SOMETHING to throw rocks with than nothing...I wouldn't turn either one down when it comes down to it.
