223 vs 556?

[brewer12345]

I am in the process of acquiring a Henry single shot in 556. I have plenty of factory ammo to shoot in it, but will be working on reloading before long. I know it isn't safe to shoot 556 in a 223 gun, but that the reverse is safe. Looking at reloading dies and data, it seems that most of it refers to 223. Can I use the same equipment on 556 brass? How is loading data different? Assume I need to segregate the brass? You can tell I find this confusing...

 

[Metal God]

Looking at reloading dies and data, it seems that most of it refers to 223. Can I use the same equipment on 556 brass?

Yes

How is loading data different?

Well it's not really , when comparing apples to apples in my Hornady or Sierra manuals the 223 data seems pretty much the same as the 5.56 with some 223 loads showing more powder then 5.56 loads when using the same bullet or bullet weights . As long as you are starting the load at minimum charge and working your way up you should be gtg regardless of what you say/think you're loading 223 or 5.56 in your head . I think of them as the same thing when reloading my own . They use the same powders , cases , primers-ish , bullets . Just start low and work your way up . If you have concerns about shooting a 5.56 pressured load you developed in a 223 rifle . Don't , just work up a new load for the 223 rifle using the same components . You will almost always be able to get to the other loads charge but not always .

Assume I need to segregate the brass?

Just by head stamp but not by 223 and 5.56 NATO . Some may say the NATO brass is thinker resulting in less allowable case volume . That is less true with 5.56 NATO brass then it "can" be with 7.62 NATO brass . . As I'm sure you know and or have read if you change a component , drop your charge by 5 to 10% and work your way back up .

I personally almost always load for accuracy first before high velocity so I often find my most accurate load well before I get to max charge .

 

[243winxb]

Above covers it well. Old info, but stiil a interesting read. http://www.accurateshooter.com/cartridge-guides/223rem/

 

[GunnyUSMC]

This may help also.

 

[brewer12345]

Thanks, guys. Never paid any attention before because ars are not really my thing. However, I am thinking a modestly loaded 223 would do wonders for turkey and jackrabbit.

 

[Galil5.56]

This may help also.
View attachment 824527

Nice visual to clearly understand the situation.

 

[Galil5.56]

I really like reviewing data from Ramshot, where they list std .223 SAAMI 55k psi max loads, 62,350 psi 5.56x45 NATO loads, and custom long throat .223 data. Really great to see them go to this length with their free online manual, and I have found them my favorite propellant 'maker' to deal with.

http://www.ramshot.com/wp-content/uploads/2018/11/WPHandloading-Guide-7.0-Web-REV.pdf

 

[Blue68f100]

The 223R has a pressure rating of 55k psi vs the 62k psi the 5.56 runs.

There is a lot of commercial 5.56 ammo on the market that are loaded to 223R levels. All depends on what you buy. The Wydle chamber 223R has long leads the reason it can shoot 5.56 ammo.

 

[otisrush]

This may help also.

That graphic is fantastic. I remember reading years ago how the 5.56 has a longer throat, but I've never seen it stated precisely in a freebore spec comparison like that graphic does.

I don't know if this is correct - but I'm concluding the danger of firing a 5.56 in a .223 is not because the *spec* for the 5.56 is higher pressure. (5.56 is - what - order of magnitude at 60-62K psi vs 55K for .223? That's 10%. I would think guns would be designed to take higher-than-spec pressures. Just a gut feel - but 10% seems like it would be in the realm of what it might be able to handle.)

The *real* issue it seems to me is that a 5.56 round loaded for that longer freebore, when put in a shorter-freebore .223, could jam the bullet into the lands, and *then* you're potentially talking pressure spikes well in excess of the 62K psi for a "normal" 5.56 round.

Thanks for posting that. Good stuff.

OR

 

[GunnyUSMC]

I have a Winchester Featherweight Mod. 70 in 223. My favorite groundhog load is a 50gr Nosler Ballistic Tip that I push at 3000 FPS. I would never shoot it in one of my ARs.