Questions About .223 and 5.56 NATO

researched diffs of 5.56 NATO and .223 Rem

I looked into the differences between the .223 Remington round and the 5.56mm NATO round. I get it. The specs for the two cartridges are close; but not the same. If pressed, one can fire a .223 round in an AR-15 chambered for a 5.56mm NATO round, but not the other way around due to the higher power inherent in the 5.56 round; and even that depends on the weight of the bullet.

I also read that one must look on the barrel to see how the weapon is chambered; it is stamped on the barrel…to be sure. As I mentioned, one can shoot a .223 round in the 5.56 rifle, but may lose some accuracy at longer distances.

Why build when one can buy complete? This is a good question and those of you who have been around firearms whether in the military or raised with guns, have an advantage to those of us who haven’t. I am starting to see how one can buy an M4 platform, that will allow, depending on lower and upper receiver combos, one to change out between AR-15, 7.62X39 (AK-47), and 300 blackout.

For a few thousand dollars one can have several options on how one wants to shoot; defend, patrol, sniper.

For myself, I am looking to purchase an AR-15 already built, chambered in a 5.56 NATO…because I can shoot both rounds and I am not concerned initially about being super accurate at distances over 60 yards.

chrome lined barrel? why or why not? Chrome lined barrels extend the life of your weapon by about 5000 rounds from what I have read.

complete gun without sites?

what about sights? so damn many out sights, optics, lasers…how does one choose?

Most of the lower end priced AR-15 come with what is called ‘flat top’. I take that as no sights at all.

Well  shit. I don’t care how good you are, ya gotta have sights. Whether iron or peep or scopes or optics or red dot or green dot or laser or whatever the hell is out there.

Red dot sights are $400. That’s pretty steep if you just spent $800 on a rifle.

What’s with the carrying handle? Is it part of the sight? Fold down, flip up geez, a rookie would get screwed buying a gun without having a clue, and probably many buyers do.

Do ya need a sling if ya gotta carrying handle? Like belt and suspenders?

I am still looking and I am getting smarter.

is there a site out there that splains all? I have not found it…

A final note on ammo; from what I have read, .223 is cheaper than 5.56 NATO. The 5.56 round was invented so that bullet would still be hypersonic at 500 yards out of the muzzle. Let’s see…sound travels roughly at 1000 fps…500 yards is 1500 ft.

Our pal Stakz has a really impressive post on .556 ammo here.

You experts out there don’t stomp on me if I got something wrong. This blog is about information; not being corrected.




4 thoughts on “Questions About .223 and 5.56 NATO

  1. .223 or 5.56 really doesn’t matter. The tolerances are so minute as to make little difference and somewhere there is a link to one of the big ranges that explain it all and they claim they use both interchangeably between rifles and rounds for 10’s of thousand of rounds with no issue per rifle.

    Chrome bolt and barrel are important because it increases the life of the rifle and reduces issues with residue build up and poor cleaning. It increases the cost a lot though but if you are not familiar with complete disassembly of the bolt carrier it can be advantageous.

    I recommend a minimum of a 1 in 9 twist on the rifling as that will allow you to shoot the weightier bullets like the 62 grain up to medium distances with reasonable accuracy. Go 1 in 7 twist if you really want to reach out and touch something with a heavy bullet though.

    About the only AR’s that you see with the old fashioned carry handles are the ones meant to look like the old M-16’s. I have one but they are much harder to buy scopes for and the scopes tend to get knocked off easier. These days carrying handles are a thing of the past I have mine for nostalgia reasons more than anything else.

    Personally I wouldn’t mess with a regular AR if I didn’t have a lot of experience with them already. I would spend the bucks and buy a Ruger SR556 top line model with the gas piston system. They are much cleaner to shoot although there is a learning curve with the recoil adjustments depending on rounds you use and mine is sometimes a bit picky about cheaper ammo. They are pricey though and a bit on the heavy side.

    All that being said though the best AR 15 I have ever owned was a short heavy barreled DPMS low end rifle that I picked up for 600 bucks about 7 years ago. Had a moly-chrome barrel which I still don’t know exactly what that means and a regular steel bolt. Was an old style M-16 look with a carry handle and that thing is still a tack driver but man does it gunk up fast though.

  2. Sounds like you are about to jump in with both feet. Beside your reasoning between .223 and a 5.56 chambered barrel the biggest plus of a 5.56 chambered barrel is that it is intended to operate at higher pressures. Melonite vs. chrome lined barrels is also another discussion but for most it doest matter as much as the gun will never get shot enough to wear it down where it makes a difference. There is also the in between 223 Wylde chamber that handles both…

    Colt used to be the standard but quality has fluctuated over the past few years – it is still a decent rifle but for it’s current price there are better guns. Where you need to spend your money is on the barrel for the upper receiver. The internals of a lower can be upgraded easily with a completion spring set or a trigger assembly.

    A decent quality complete lower can be had for less than $200 (Palmetto State Armory). I would not recommend having one lower and changing out the upper for a change in calibers as the wrong bullet can make things go ka-boom.

    Lots of choices. I currently have an older Bushmaster with a 5.56/.223 barrel and a 6.8 SPC that I put together as my two AR’s.

  3. Ha, amazing how great minds think alike. I’ve been researching the same stuff. I like pistols for target practice; but I’m going to buy an AR15 “just because”.
    I’ve settled on the 5.56 as the round of choice for the same reason; I can shoot the .223 if I have to. I’m going to get the stock, plain jane model; you can always dress her up later. My son has one with a red dot scope, boy does that make a difference. A much quicker capture of the sight picture. But like you, I can’t afford the $400. Some day.

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