Texas M4??

[KBCraig]

OK, here's my chance for validation or correction about lowers and uppers. Of course lowers don't have a caliber, but my understanding is that the BATF requires that the caliber of the upper must agree with the caliber markings on the lower. In other words, while a 6.8SPC upper would fit on a 5.56/.223 lower you could be in trouble if say a BATF agent happened to check. That's why they make multi-caliber lowers so you can avoid problems. I haven't made a huge effort to find the BATF reference, but I've heard this to be true by "those in the know." Fire Away!!

Sounds more like gun shop or internet "expert" lore to me. I've never heard of any such ATF requirement. It wouldn't even make sense (not that ATF makes much sense), because the lower does not fire ammunition. The modularity of the AR design means you can slap multiple uppers (in multiple calibers) all on the same lower, and in some cases you can use unmodified magazines for different calibers.

It's worth pointing out here that if you own multiple caliber uppers, they should be marked in a distinct way if they're not 5.56 or.223!

[flintknapper]

OK, here's my chance for validation or correction about lowers and uppers. Of course lowers don't have a caliber, but my understanding is that the BATF requires that the caliber of the upper must agree with the caliber markings on the lower. In other words, while a 6.8SPC upper would fit on a 5.56/.223 lower you could be in trouble if say a BATF agent happened to check. That's why they make multi-caliber lowers so you can avoid problems. I haven't made a huge effort to find the BATF reference, but I've heard this to be true by "those in the know." Fire Away!!

Incorrect.

Unless some recent law has been enacted, you can put any compatible upper you want on a lower. This assumes it does not violate any State/Local laws or ordinances (such as 50 cal. restrictions).

[bdickens]

The 5.56 round is ever so slightly larger than the .223 maybe somewhere in the ten-thousanths range. Manufacturing tolerances being what they are, if you have a round of 5.56mm ammunition that is on the large side of the range and a .223 chamber that is on the small side, you can get extraction failures.

[dihappy]

I love all this info :P

So, before i go out and get a 5.56 because i can use either round, what is the negative about getting just a .223?

Is 5.56 cheaper? More abundant?

All things being equal, is any one caliber more accurate than the other?

[WEC]

From my experience, it's much "easier" and "less expensive" to find .223 Remington. This is just a generalization.

[flintknapper]

I love all this info :P

So, before i go out and get a 5.56 because i can use either round, what is the negative about getting just a .223?

None really.... depending upon your intended use. If you want to go out and rapid fire your weapon alot, then I would select the 5.56 (with it's more generous tolerances). If you plan to shoot your weapon a bit slower and want the best accuracy, then I would choose the .223 chambering.

Is 5.56 cheaper? More abundant?

You can find surplus ammo that is definitely cheaper than commercial stuff.

All things being equal, is any one caliber more accurate than the other?

Of course, "all things" are not "equal" concerning the chambers for the two rounds. The 5.56 has a different freebore diameter, freebore length (Leade) and chamber angle. The "Leade" is roughly twice a long as compared with the .223, this can affect accuracy. Basically, if you want the ultimate in accuracy...get the .223 and use quality commercial ammo (or handload). You can also get the "Wylde chamber" which is a compromise between the 5.56 chamber leade and the .223 and allows you shoot both cartridges with good accuracy.

Anyone wanting information on the AR-15 platform (and all it's cartridge variants) should go to (AR15.COM)
http://www.ar15.com/forums/forum.html?b=3&f=4" onclick="window.open(this.href);return false;

[Kythas]

Excellent price for an M4. Wish I saw this link before I bought mine at the gun show this past weekend - I would have saved almost $300-400, depending on tax and FFL fee.

BTW - with a 1/9 twist, you can shoot 69gr ammo, but I wouldn't go above that.

[ELB]

The most informative single thread I have run across about AR-15s (for serious purposes) is this:

"So You Want to Buy an AR-15, huh?"
http://forums.officer.com/showthread.php?t=81462" onclick="window.open(this.href);return false;

In reference to whether to get .223 vs 5.56, as far as I can tell it depends on whether you want a reliable, combat accurate self-defense rifle or a highly accurate target rifle. All the things that seem to increase accuracy (as far as tolerances go) also seem to decrease reliability by providing less tolerance for sightly-out-of-spec rounds, dirt/burned powder, expansion from heating, and so forth.

break- break

gtdist.com ran a sale on the Texas M-4 when they first started supplying DPS with the rifle a year ago or so (I am fuzzy on the date). It was even cheaper then, and came with extra magazines. Thought really hard about it then, but decided to stick to 7.62 x 39.

[dihappy]

Yes my buddy was there the other day and said they were still selling it with the extra clip.

I hope they are still taking orders when i have the money. I thought about getting the parts separately and putting one together, however i dont know how difficult it will be to get parts if i take to long to collect them.

[dihappy]

The most informative single thread I have run across about AR-15s (for serious purposes) is this:

"So You Want to Buy an AR-15, huh?"
http://forums.officer.com/showthread.php?t=81462" onclick="window.open(this.href);return false;

In reference to whether to get .223 vs 5.56, as far as I can tell it depends on whether you want a reliable, combat accurate self-defense rifle or a highly accurate target rifle. All the things that seem to increase accuracy (as far as tolerances go) also seem to decrease reliability by providing less tolerance for sightly-out-of-spec rounds, dirt/burned powder, expansion from heating, and so forth.

break- break

gtdist.com ran a sale on the Texas M-4 when they first started supplying DPS with the rifle a year ago or so (I am fuzzy on the date). It was even cheaper then, and came with extra magazines. Thought really hard about it then, but decided to stick to 7.62 x 39.

ELB,
I certainly would like to get something i could use reliably for self defense and of course, occasional target shooting.

And since i am leaning towards self defense, i was actually even giving thought to a .308 as well, maybe both.

[flintknapper]

The most informative single thread I have run across about AR-15s (for serious purposes) is this:

"So You Want to Buy an AR-15, huh?"
http://forums.officer.com/showthread.php?t=81462" onclick="window.open(this.href);return false;

In reference to whether to get .223 vs 5.56, as far as I can tell it depends on whether you want a reliable, combat accurate self-defense rifle or a highly accurate target rifle. All the things that seem to increase accuracy (as far as tolerances go) also seem to decrease reliability by providing less tolerance for sightly-out-of-spec rounds, dirt/burned powder, expansion from heating, and so forth.

break- break

gtdist.com ran a sale on the Texas M-4 when they first started supplying DPS with the rifle a year ago or so (I am fuzzy on the date). It was even cheaper then, and came with extra magazines. Thought really hard about it then, but decided to stick to 7.62 x 39.

ELB,
I certainly would like to get something i could use reliably for self defense and of course, occasional target shooting.

And since i am leaning towards self defense, i was actually even giving thought to a .308 as well, maybe both.

The 5.56 or .223 should do fine for you. Unless you have really deep pockets...you will be able to shoot more (practice) with the 5.56 than with the .308 (AR-10).

If you don't feel the 5.56 is enough for self defense, then you can build 7-8 variants off of a 5.56 lower. Just buy whatever upper you think would suit you and put it on your lower.

The .458 SOCOM will fit the 5.56 lower, uses the same magazine as the 5.56-.223 and will shoot a host of bullets from 250 grs. to 600 grs. (that ought to be powerful enough). Of course, commercially loaded rounds go for about $55.00 a box (20 rounds)...so just getting it sighted in could get expensive.

The great thing about the AR platform (whether 5.56 or .308) is that the rifle is so "modular". Just get the lower you want and put different uppers on to accommodate your wants/needs.