.223 vs 5.56

[jedi]

AR n00B here. Search did not find anything.
In planning for my AR build which upper caliber should I get: .223 or 5.56?

I have read that a 5.56 upper can use .223 but a .223 cannot use 5.56 (due to the added "power" of the round).

Ammo wise which is cheaper .223 or 5.56?
Which is more avaliable?
Reloading wise do I need to worry about either?

Plans for this AR would be just as a learners AR. It won't be SHTH or defense. That is what SG and AK are for. Won't be doing compeition shooting either. The AR will have primarily a .22 upper and this other upper will be used as "backup" to bring the shooter up from .22 to bigger round.

Thanks

 

[haldir]

Get a 5.56. Like you said, then you can shoot either.

 

[firstrock]

I'd get a 5.56 upper so you don't have to worry about 5.56 vs .223 ammo, just load up a mag and go!

I'm not sure on availability but I tend to see more .223 or retail shelves than 5.56, but both are available.

I'd think the 5.56 would be a tad more expensive to reload but not by enough to justify only using .223.

Just go with the 5.56 and don't look back!!

 

[Mr. Habib]

I would buy a 5.56 upper to be able to shoot both .223 and 5.56. Then cheaper and available both become nonissues. As far as reloading goes, you will find far more loading data for .223. I don't know of any manuals that list military loads for 5.56x45. If you reload military brass you may have some issues with crimped primers, but those can be dealt with,with the right equipment. Here is a link to a pdf showing the differences between .223 and 5.56 chambers. http://www.ar15barrels.com/data/223vs556.pdf

 

[esrice]

I would buy a 5.56 upper to be able to shoot both .223 and 5.56. Then cheaper and available both become nonissues.

Yep.

 

[NateIU10]

5.56 so you can shoot both and you aren't looking for match-grade results

 

[tharlow514]

Plans for this AR would be just as a learners AR. It won't be SHTH or defense. That is what SG and AK are for.

Thanks

I like AK's as well but just curious why you would not want an AR for defense? They are great for defense IMO. That being said, I would definitely go with chambering in .556

 

[eears]

Thanks for the info on the difference in 223 and 556. I have talked to so many people that say they are all the same. I think going 556 is a no brainer.

 

[jedi]

@ eears
Here are some sources on why you can not shoot 5.56 in a .223 chamber.
What is the difference between 5.56 and .223 ammo and can they be fired from the same rifle? - Yahoo! Answers
This is NOT the exact source I first found but does give the same info.
In a nutshell which the physical casing may be identical or very, very close the 5.56 uses a much strong powder so thus produces more gas. The .223 barrel was not designed to withstand that much pressure from the gasses and could rupture (aka blow up).

@tharlow514 I'm going to get an earful from the AR fanboys but the AK is a much more "reliable system" in terms of the ammo will fire no matter what condition the gun is in. Dirty, rust, grease, sand, etc.. the AK does not care it will fire. Now it's not a system designed to go the distance (long range). For that the AR is a much better system in terms of precision hitting. However the AR must be kept clean and well maintained in order to operate. I'm not saying I don't clean my guns but for my SHTF planning I sticking with the basic AK design that is simple to learn (for even a non gun user), easy to teach, requires very little cleaning, uses a more powerful round that can go thru hard targets and has a long proven track record of working no matter what condition the firearm is in. The only downside is the lack of ammo for it in a SHTF. Thus you have to ensure you supply your own (think 1000s of rounds) for it.

AR fan-boys away! I know its the same classic debate of 1911 vs GLOCk, Ford vs Chevy, 9mm vs .45. For me I'm keeping my AK for short to mid fighting as I don't see myself doing any long range fighting in SHTF.

 

[boman]

The .223 barrel was not designed to withstand that much pressure from the gasses and could rupture (aka blow up).

Big Myth---barrel steel is the same (4140 - 4150 are the most common ).
The diff is the chamber dimensions---5.56 chamber dimensions are more generous than 223 dimensions. One can experience higher pressures when shooting the military spec. ammunition in a 223 chamber but won't blow a barrel up. one might damage a bolt or firing pin, ejector etc. but even that's not likely.



Steve

 

[jedi]

Big Myth---barrel steel is the same (4140 - 4150 are the most common ).
The diff is the chamber dimensions---5.56 chamber dimensions are more generous than 223 dimensions. One can experience higher pressures when shooting the military spec. ammunition in a 223 chamber but won't blow a barrel up. one might damage a bolt or firing pin, ejector etc. but even that's not likely.



Steve

Here is the original source I read on this 5.56 vs .223 issue.

Gary Conway's AR15 Website

 

[melensdad]

5.56 or 223 is not something that is a no-brainer. While it seem that everyone in this thread jumps through hoops to recommend the 5.56 I have not seen anyone suggest the advantages for the 223 so I'll offer a counter viewpoint.

DEPENDING ON THE PURPOSE of the gun, there is potentially a significant difference between the choice. For extreme accuracy you will find guns chambered for 223 and not 5.56. So if your gun is going to be a varmint gun, shooting the heads of chipmunks at 250 yards, then you'd want a 223. Going for tiny groups at longer ranges, again you'd want a 223.

I look at rifles the way I look at cars, tools and tractors. Want a tractor to plow a field, get a heavy machine like a New Holland for traction. Want a tractor to mow a nice lawn, then get a light weight Kubota so you don't rut the lawn. Want to go fast down the highway then get a Corvette. Want to haul you child back and forth to college then take a look at a Suburban to hold all the luggage. Need to drill holes through heavy steel, then pick up a 1/2" chucked Milwaukee corded drill. Need to work on a ladder while drilling holes in soffits made of wood, pick up a light weight battery operated drill.

Guns work the same way.

You need to first decide on the TASK that you want to perform, then let that task dictate the caliber and the configuration that will best perform the task with the least number of compromises and the greatest likelihood of effectiveness.

Hope that makes sense.

 

[Big Hank]

I know I could research this, but what are the actual diameters of a .223 and 5.56? I know it can but it's odd to me that the 5.56 can do both just because 5.56 is .219 when converted and rounded up. Thanks for expanding on this.

 

[esrice]

I know I could research this, but what are the actual diameters of a .223 and 5.56?

:: Ammo Oracle

 

[hc4sar]

www.6mmbr.com

 

[jedi]

5.56 or 223 is not something that is a no-brainer. While it seem that everyone in this thread jumps through hoops to recommend the 5.56 I have not seen anyone suggest the advantages for the 223 so I'll offer a counter viewpoint.

DEPENDING ON THE PURPOSE of the gun, there is potentially a significant difference between the choice. For extreme accuracy you will find guns chambered for 223 and not 5.56. So if your gun is going to be a varmint gun, shooting the heads of chipmunks at 250 yards, then you'd want a 223. Going for tiny groups at longer ranges, again you'd want a 223.

Thanks did not know that .223 was "better" for accuracy than 5.56.

 

[melensdad]

Thanks did not know that .223 was "better" for accuracy than 5.56.

Well it is more related to the chamber than the bullet/cartridge. The 5.56 chamber is much looser and the lands and grooves are farther forward. The 223 chamber is made tighter with the ability to seat the bullets so that they are nearly in contact with the rifling.

As for the rounds themselves and the accuracy between the 223 and the 5.56 that will really depend upon the quality of the components. Surplus junk will never shoot as well as carefully loaded ammo, no matter what caliber designation.

Accuracy is also, in part, related to the bullet weight and the twist rate. If they are not compatible then even the best ammo will shoot shotgun accuracy groups!

 

[tharlow514]

@tharlow514 I'm going to get an earful from the AR fanboys but the AK is a much more "reliable system" in terms of the ammo will fire no matter what condition the gun is in. Dirty, rust, grease, sand, etc.. the AK does not care it will fire. Now it's not a system designed to go the distance (long range). For that the AR is a much better system in terms of precision hitting. However the AR must be kept clean and well maintained in order to operate. I'm not saying I don't clean my guns but for my SHTF planning I sticking with the basic AK design that is simple to learn (for even a non gun user), easy to teach, requires very little cleaning, uses a more powerful round that can go thru hard targets and has a long proven track record of working no matter what condition the firearm is in. The only downside is the lack of ammo for it in a SHTF. Thus you have to ensure you supply your own (think 1000s of rounds) for it.

I think you make some valid points. I like how reliable the AK is and I agree that they are more reliable than the AR. I have been wanting to add an AK to my arsenal for a long time and that is the reason why. I do think the ergonomics of the AR makes it a more comfortable gun to shoot. I guess I just need to have both Thanks for your input and sorry to get off topic.