Home Forums Hunting & Shooting AR and Tactical Rifles what are the pro/cons of .223 vs 5.56 in an ar15?

I'm considering an ar15 in the near future. I'm just wondering if there is any benefit of getting 5.56 vs 223 if I can find the gun in the configuration I want? I realize I can shoot 223 in a 5.56, but not the other way around. I will porbably ONLY buy 223 or reload 223 cartridges, so is there any real reason to buy a 5.56 when there are a lot of ar15's chambered specifically for 223?
Is there be any loss of accuracy in a 5.56 using 223 ammo?
My most likely usage will be varminting (pdogs) with a scoped gun.
Thanks for the info, and sorry if this has been answered before. I searched but couldn't find any posts answering this question.

Get a gun with a wilde chamber, it's a match type chamber that will take either 223 or 5.56 ammo.

Benefit of a wilde vs the others? A 5.56 will take both 5.56 and .223, right? How does a wilde improve on that?
I'm not trying to be dumb, just want to know answers.

I read this on the RRA website: "The .223 Wylde chamber was designed as a match chambering for semi-automatic rifles. It will accomodate both .223 Rem and 5.56mm NATO ammunition. It is relieved in the case body to aid in extraction and features a shorter throat for improved accuracy."

So, can I assume that it is mainly supposed to be more accurate because of these features than simply a 5.56, since the 5.56 can shoot both chambers, anyway.
AND, if the wylde is better, why not make EVERY ar15 that way?

reality is that there are not many 223 chambers that won't be just fine with 5.56....

Searching for a gun chambered 5.56 with a wlyde chamber though would be best of both worlds and for sure safe if you stumble into a good deal on 5.56 ball etc.....

Why not every AR is chambered with Wylde is a good question, unless we are talking specific match chambers...

Some in the "tacticool" crowd insist that their AR's be built to military specs, so their chamber just has to be 5.56 spec, because it's a gun their life depends on, though I imagine well less than 10% of the "working" guns are used for that.

As to .223 chambers, many shooters are only going to put commercial .223 ammo through their guns.

For your application, the wilde is the best way to go.

I bet its far less than 10%.... I"d bet that probably 99% of the folks that rely on them for their life are issued weapons...

That tacticool crowd is a bunch of idiots....

Simply put, and from my own experience, the Wylde chamber makes extraction problems much less likely, and it does make the barrel more accurate. Rock River Arms offers many models with the Wylde chamber. What's not to like?

A slightly more generous chamber to ease extraction, and a shorter leade for the projectile to jump to the lands = much better accuracy. If you also go with the stainless steel barrel, you also have the benefits of a chromed bore. Easier to clean, corrosion resistant, longer lasting, without the slight loss in accuracy. If you're only going to have one AR, why not spend just a little more and do it right the first time?

stainless steel barrels do not last anywhere near the life span of a chrome lined barrel.

Yeah, but are there any chrome lined barrels that shoot on par with the ss barrels?

My last SS barrel could no longer hold the 0.5 MOA X-ring after 5000 rounds so I pulled it and replaced with a new SS barrel. On the other hand that 5,000 round barrel could hold 1MOA quite well and would probably be able to do that for another 5,000 rounds at which point it would start to be about as accurate as a brand new chrome-lined barrel.

It all depends on what your expectations are and what you mean by "barrel life".

There are no chrome barrels that I'm aware of that are reliably IE every last one... that makes MOA or better. MOA is more than enough for most folks.

Barrel life wise I've seen a couple of chromed MOA or less barrels that went well over 15K rounds of accurate life. While most of my SS barrels are no longer capable of MOA at around 8K or so rounds. I drove one once to almost 12K rounds, a SS Krieger... it was over MOA though but could still win matches with it.

My previous post did not answer your original question so I will do that in this one.

What really makes a 5.56 NATO cartridge is the use of the SS109 type bullet (62gr FMJ with 10gr steel penetrator) at 62,000PSI if memory serves. Because of the shape of the bullet, (it has a very bulbous ogive,) and the fact they pack a lot of powder in the case, there is a very realy possibility the chambered cartridge will have its bullet contacting the rifling in a tight .223 chamber, with a short leade. This type of bullet is not designed to be loaded into the lands of the barrel and so the initial pressure may climb higher than expected as the bullet tries to engrave itself into the rifling without its usual running start. If you add in the higher pressure at which the 5.56 is usually (but certainly not always) loaded, yu could get quite a pressure spike, again in a tight .223 match chamber.

But this is only using this bullet, the SS109 in the M855 ammo and that is the only 5.56 NATO loading.

The NATO chamber is also made looser than required for 2 reasons; 1- it is supposed to be able to chamber any NATO ammo made by any country that produces NATO ammo so the variations have to be taken into account. 2- The M16 with NATO chamber is a martial weapon, designed to be used in all conditions, including mud, sand, snow, rain, etc. abd as such must be able to load any NATO ammo under less than clinical conditions.

The .mil is not interested in gilt-edged accuracy out of these rifles, with this ammo; the minimum accuracy of this combination is 4MOA.

I have AR-15s with NATO chamber, Wylde chamber and 5.56 Match chamber. The last one is a product of Krieger barrels and it is a VERY tight .223 chamber with a long leade to accomodate my 80gr bullets seated out to 2.45+. I can assure you that my LR match loads are even higher pressure than the 5.56 NATO rounds, but I take other steps to tame the pressure curve. I used to swear by the Wylde chamber in the prior incarnation of this rifle's barrel, now I swear at it for the good reason that none of the brass that I used to shoot in it can function properly in this match chamber. So, I had to get new brass for this barrel and I must make sure to never use this brass in the evil Wylde or NATO chambers.

I would never use this match rifle in a situation where perfect funtion is required at all times, or even rapid fire. This is a match rifle, dedicated to one purpose only; competition.

On the other hand, I am now talking my Wylde-chambered National Match rifle hunting. It has never failed my in Service Rifle competition where rapid fire is required and it is more accurate than my NATO-chambered ones. It's does not have the high degree of accuracy that my match rifle has and requires, but Service Rifle did not require that degree of accuracy and certainly neither does hunting or even varminting.

So, what does this all mean. If you buy ammo and you insist on using M855 equivalent only or greatly; you need a NATO chamber. If you want great accuracy and reliability and the capability to shoot M855 junk at time, you need a Wylde chamber. If you handload and you need superb accuracy, you need to get a .223 match chamber and tune your loads to the rifle. You may want to make sure it can handle the bullets you want to use, if you're looking at longer ones.

FOr the purposes you have stated, I will add my vote for a Wylde or equivalent chamber. Yes, there are several different chambers that accomplish the same thing as the Wylde but the later is more prevalent.

Finally, and this is where an argument can start, I suggest you get a 1:8 twist and no faster, with your Wylde (or equivalent) chamber and get it in a stainless steel barrel.

Yeah, but finding one is the luck of the draw. I have a Colt that has a chrome lined barrel that is MOA to 600 with both 69 gr SMK's and 80 gr SMK's, which is as far as I've shot it. Then I have some Bushies with chrome lined barrels that are lucky to be 2+ MOA.

Better to spend the money on a top notch barrel maker chrome moly NON chrome lined barrel or SS from the same if you want top accuracy.

I read an article back in the early 00's from Precision Shooting that did some research on accurate barrel life differences between SS and chrome moly, and the latter came in the winner by a couple of thousand rounds. IIRC, it has to do with sulphur content in SS barrels creating inclusions that cause the barrels to lose accuracy faster than chrome moly tubes due to erosion of the inclusions. I've slept since then and have forgotten the exact issue in which the article was published, but was kind of surprised after I read it.

I agree totally... and is why I"v asked now and then.. no one has ever said there is anyone coating them thats good and reliable.

Personally I think what I"m still hearing about Ultra Bore Coat or whatever its newest name is, that coating an SS barrel might give the best of all worlds.

The only downside to that would be the fact that still to this day, SS dies instantly but CM shows degredation so that you know its dying.... SS I shot this 200-17X rapid fire prone once.. and the next string of course is 22 at 600 and could not hold the ten ring, I think it was very low 190s and I normally could shooot a 200 or close

thanks for all the info, guys.
I'm not at the place to purchase yet, but with this info, leaning to wylde chamber. I'm not likely to spend the extra $$ on a match 223 bbl. I'm also much more likely to just buy the whole gun somewhere and not parts. POSSIBLY I would get an upper & lower separate, but who knows.
I like the info i've seen on RRA and 3/4 moa accuracy guarantee with those guns.

New question: 16, 18, 20 or 24" bbl? I'm leaning to one in a 20 for a little extra velocity.
And, if I went with the Varmint model (RRA), do I want the EOP or the standard A4? Or how about the predator pursuit? That seems to me to be about the same as the varmint with a slighter bbl.
thoughts?

If you believe the 3/4 MOA accuracy guarantee, I would like to interest you in some beachfront property with a bridge to boot. If you do not produce 3/4 MOA groups, it will be your problem not RRA's because they can do it any time, I'm sure.

RRA is a good brand, I happen to be more inclined to ArmaLite, others will mention various other vendors.

The good thing about a complete rifle is that you get a warranty.

As for your question, the answer is simple 20 inch is the optimum barrel length if you want to carry the rifle around and shoot it without a bipod. If you want longer reach, 24 inch is the way to go.

What is a slighter bbl?

by slighter I mean smaller in diameter. I'm figuring the varming has a bigger bbl than the predator. Why didn't I just write that, then???

If you reload and can't get to .75 moa with a Wilson tube in an RRA gun it would be the first I"ve ever seen that wouldn't do it. I have seen 2 that needed to be recrowned.. at one point it seems like their "crowning" person used a 3/8 drill bit... but I have not seen that issue in a number of years. Thats .75 moa at 100 yards. There is a difference at longer ranges. Whether you need more or not is up to you.
On the Armalite, at times I"ve seen them not function as a complete rifle out of the box so each vendor can have its own issues at times.

You can't really go wrong with the normal builders. Weight is an issue up to you, weight really doesn't have much to do with accuracy bascially.
Barrel length is also personal, personally I dont' see anything over 24 inches being a big bonus. But you can loose a lot of speed under 20...

I'd have to agree with Jeff. Unless you're doing for real CQB, riding around in an armored vehicle or gaming, there's absolutely no advantage to a tube shorter than 20". For a stationary varmint gun I'd go with 24". A walk around varmint/hunting rig would get a 20" barrel. That's my personal preferences, but hey, it's your rig, do what you like, not what someone else thinks you should like.

I like 20", which is why I ordered a predator persuit upper. It's not so much the velocity loss of the 16" tube, it's the muzzle blast when shooting at a covered range. Even with plugs and ear muffs, I just don't care for the feeling of a small concussion grenaded going off in my face with each shot.

Still a couple months before my upper shows up, so we'll see how well it shoots. I would be suprised if I couldn't find a handload that will print 5 shots into 3/4" at 100 yds. I won't be suprised if I find a load that'll go into 1/2" at 100 yds.

I purchased an RRA lower with m4 stock and national match trigger a year or so back and have been debating uppers ever since. The predator persuit seemed like the perfect match of accuracy potential, and yet not to heavy to use as a carrying varmint rifle. The A4 upper is the way to go as you'll want to mount the scope forward and that's easier with the A4 upper. As my kids and wife shoot my guns, the A4 stock is more flexible, but if it was a gun for just me I'd go with a fixed stock.