Thread: To continue my education on AR15s 223 chamber v 5.56mm

So all else being equal from what Ive read so far I would be better off with a .223 chamber for accuracy? So something like a NEA15 in 5.56mm shooting .223 ammo is best avoided unless its chambered in .223?

or does it not matter?

I rather liked this piece,

http://www.luckygunner.com/labs/5-56-vs-223/

regards

The .223 Remington is the most widely-used centerfire rifle cartridge in the developed world. In its 5.56×45 military form, it is the primary issue ammunition for the U.S. Military and NATO forces. It is a popular sporting cartridge, and probably the most commonly used centerfire varmint cartridge.

In our Readers’ Poll, the .223 Rem (both standard and improved) ranked first among preferred varmint rounds. The .223 Rem is efficient and versatile. It can sling 40-grainers past 3650 fps, and deliver 90gr VLDs accurately at 1000 yards. Its parent case, the .222 Remington, was once a mainstay of benchrest competition. Today, with custom match bullets, the .223 Remington can still deliver impressive accuracy, shooting well under quarter-MOA in a good rifle.

.223 Remington Cartridge History
The .223 Rem traces its roots to the .222 Remington, a round popular with benchrest and varmint shooters in the 1950s. When the US military was looking for a new high-speed small-caliber round to replace the .308 Winchester (7.62×51), Remington started with the .222 Remington, and stretched it to increase powder capacity by about 20% in 1958 to make the .222 Remington Magnum. The cartridge was not accepted by the military, but it was introduced commercially. In 1964, the 5.56×45 mm, also based on a stretched .222 Rem case (and very similar to the .222 Rem Magnum), was adopted along with the new M-16 rifle. As with the .222 Rem Magnum, the new military case achieved enhanced velocity (over the .222 Rem) by increasing case capacity with a longer body section and shorter neck. This military modification of the .222 Rem was originally called the .222 Special but was later renamed the .223 Remington. In military metric nomenclature, the round is called the 5.56×45. For the full history of the 5.56×45 cartridge, read the 5.56×45 Timeline, by Daniel Watters.



Source for Name-Brand Factory .223 Rem Ammo: LuckyGunner.com LuckyGunner.com Ammo




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im an idiot , I just realised it was the same link you just put up ...... please ignore double posts ......

Summary: Buy a well-made rifle with the chamber you want based on your needs, shoot the right ammo in it, and have fun. For most people, especially those not sure of what type of shooting they’ll be doing, a 5.56mm chamber is the best all-around choice. It is my fervent hope that this article has helped you better understand the topic at hand.

I guess this bit of advice from the article above will answer it

Originally Posted by steven

So all else being equal from what Ive read so far I would be better off with a .223 chamber for accuracy? So something like a NEA15 in 5.56mm shooting .223 ammo is best avoided unless its chambered in .223?

or does it not matter?

I rather liked this piece,

http://www.luckygunner.com/labs/5-56-vs-223/

regards

The old theory is that it is okay to shoot .223 in a 5.56mm chambered rifle, but not 5.56mm in a .223 chamber due to tolerances, pressure loads and throat length.

Unless you plan on actually shooting mil surp 5.56mmx45 ammo (which will be FMJs) then a .223 chambered AR is fine, as you'll be buying .223 ammo generally or handloading to .223 specs.

My AR is a Lothar Walther heavy profile barreled .223 1 in 9" twist with a tight chamber and quite a short throat, tighter than even my Sako .223 bolt action.
Its not a free floated barrel, doesn't have a muzzle brake or a fancy 2 stage match trigger, so I don't worry about tighter groups than the 0.66 MOA it can shoot with handloads off a rest.

Honestly it really doesn't make much difference accuracy wise between 223 and 5.56. The NEAs in 5.56 are bloody accurate according to the majority of people with them, which tends to suggest that 5.56 guns do shoot just fine. Accuracy is more likely to be degraded by chrome-lined barrels, non-floated tubes, or running cheap ammo, or trying to shoot heavy projectiles in a 1:12 or 1:9 barrel, than by running a 5.56 chamber.

If you're really worried about accuracy, you'd be looking at a wylde or other proper 223 match chambering anyway.

Like dogmatix said, the main bonus with a 5.56 chambered gun is that you don't have to worry about going over 223 pressures, and can run any 5.56/.223 ammo without having to give it any thought. For those who like running hot loads, this might be a good thing.

5.56 guns are capable of excellent accuracy. You can run hotter loads through a rifle with a true 5.56 chamber safely. I mostly shoot a Colt mil spec barrel, even with projectiles seated to 2.20" it still shoots fine.

Ive shot sub half moa in my nea at 100 with a 3 round touching group