The Annoyed Man wrote:If you're going to have a 12 lb rifle for walking around with, why not make it a .308? See what I mean? I'm not advocating that you buy a .308. I'm just saying that one of the charms of an AR15 is its relatively light weight and handiness, combined with good accuracy. The fact is that neither of those two heavy long-barreled ARs of ours get shot very much.
Ya know, I guess I'll bring up the .308 notion again. It kinda seems that the OP, 74novaman, wants two new rifles in one, and that might not be realistically possible.
Accuracy at distance was mentioned, even out to 600 yards; while the .223 can shoot nice and flat and offer good accuracy at extended distances, IMHO small varmints or punching holes in paper is pretty much all it can be relegated to at distance.
The barrel length does make a difference in velocity achieved, and velocity adds to the potentially effective range. But the .223 is a stopper when it can strike the target near or at 2,700 fps. Its effectiveness is primarily based on the round fragmenting as it tumbles on impact. It isn't the tumble itself that does it; that's common to any FMJ spitzer-shaped projectile: as soon as it encounters a dense but soft medium and the point-forward flight of the bullet is disturbed, it will yaw and try to flip around 180 degrees and, if uninterrupted, continue the remainder of its flight base-first. It will, of course, change trajectory if it encounters a hard object like bone after entry. Unless a .223 round's jacket separates from its core as it does its tumble, it just ends up being a light, .22-caliber round that--other than the 180-degree flip which typically happens quickly at a shallow depth--makes the same size hole penetrating as it did when entering.
An older 55-grain round (M193) out of a 20-inch barrel will stay at around 2,700 fps out to around 200 yards. By contrast, the newer 62-grain M855 (SS109) round through a military M4 14.5" barrel will drop under 2,700 fps in about 20 to 25 yards. That's a big reason so many failure-to-stop reports have come back from Afghanistan and Iraq, even as far back as Paul Howe's wise observations about the Battle of Mogadishu. That, and due to its size, the .223 is notoriously poor at penetrating any kind of cover. Those are the reasons that military snipers use heavier calibers to reach out and touch the bad guys; if the lighter, smaller, and easier to transport .223 would do the trick reliably, that's what would be in play.
I guess, to me, it comes down to the real purpose for the rifle. At 350 yards, a prairie dog is no match for a .223 projectile. But its maximum effective range for larger game or defensive purposes is going to be around 200 yards; with a heavier bullet and shorter barrel, less. But 5.56 NATO is a common round worldwide, is relatively inexpensive and easy to find, and makes for a great urban or patrol-type rifle. Definitely has its place, and I think everyone should own at least one.
If shooting at paper at 400 yards is desired, go for it. However, if you want hunting or defensive purposed use out beyond 200 yards, I'd vote for a heftier caliber. There a lot to choose from above .223 while still keeping the Stoner or a Stoner-like gas piston system on an AR-15 or AR-10 platform. All the same basic manual-at-arms, which is a good thing. Ya got everything from 6.5 Grendel to .308 to .338 Federal to .458 SOCOM to .50 Beowulf, and a bunch of others in between. Some of the ammo options are, shall we kindly say, pricey.
But the one that's also a standard NATO round is the .308, 7.62x51mm. Decent but inexpensive milsurp ammo can be had for it; it offers a utilitarian hunting/defensive round for use out past 200 yards; and ammo is readily available. Not a good choice for basic home or urban-distance defense, though. Unlike the .223, the .308 can and will penetrate.
The downside is that while uppers can be interchangeable for the specific platforms, the AR-15 and AR-10 platforms use a different lower and you can't really move uppers between the breeds.
Building these things is as addictive as owning 1911s. I very much recommend planning out an annual schedule for possible builds to help keep your budget, yourself, and your wife sane.
If you're already happy enough with your AKs for urban and mid-distance stuff, and you don't live on a ranch or farm where varmint hunting is of primary concern, you may want to consider starting with an AR-10-type platform in .308. Just as accurate for target shooting, and it provides effective distance capabilities that the AK and AR-15 in .223 simply can't.
Conversely, it's going to more expensive to shoot. If you really just want a Stoner platform for paper punching, another big advantage of the AR-15 in .223 is that you can then look at a conversion kit for shooting .22 LR. Plink for pennies instead of dollars. And as TAM said, weight might matter. If you're considering taking a carbine training course, you definitely do want a lightweight rifle. Several years ago I took a class where one of the guys had a 24" bull-barrel AR-15 similar to TAM's; after the first 10-hour day of two-hour shifts standing, walking, and running with that strapped over his neck, he was not a happy camper.
Maybe an AR-15 now with your choice of barrel lengths, a .22 LR conversion kit for it next, and an AR-10 in .308 a little later in the year? That'd cover your bases. At least until you decide that you absolutely positively
need to have that 6.5 Grendel upper.
BTW, I'm not pontificatin' in your specific direction; you already have in mind what you want. But just in case new members are starting their own research...
) yet still capable of being used at closer ranges.
). So, here I wait.