[Neil Andrew]

Their is plenty of load data for the 223 Rem, but very sparse load data for the 5.56 NATO. Does anyone know of a good website?

 

[RD Myers]

Go to Hornady. Ir is listed as 223 Remington Service Rifle data. No load data on light bullets 68 and 70 grain only, at least in my Hornady manual. May be more on their website.

 

[Neil Andrew]

Go to Hornady. Ir is listed as 223 Remington Service Rifle data. No load data on light bullets 68 and 70 grain only, at least in my Hornady manual. May be more on their website.

I do have the Hornady manual, the Velocity for the 75gr BTHP Match in the 223 Remington Service Rifle ranges from 2200 to 2700 verses the 5.56 NATO which is 2500 to 2900. This Loads for the same velocity is different.

I am looking for 5.56 NATO Loads for 70 to 80 grain bullets!

 

[turable.shot]

Hornady 10 edition has 5.56 Nato, and range from 55gr to 80 gr.
Pages 174 to 178.

 

[RD Myers]

I have a Nosler and Berger manual with 77 to 90 grain load data. It's all 223 but you could start there and work your way up till you see pressure signs. The Berger has data for 80, 80.2 and 90 grain. I would post but I am not good on computers. I can take a pic and send them to you phone if you would like. Just pm me and will be glad to send it.

 

[canebreaker]

Where did you get your 5.56X45 dies?

 

[rodneygt]

I didn’t think that there was a such a thing as a 5.56x45 die, per se - just .223 dies that could be used for either??

 

[Neil Andrew]

I am using the Lee 223 Rem die set and have not had any issues. Since I am shooting the Hornady 75 gr BTHP Match bullet I am loading based from the Hornady 11th manual to 5.56 NATO. I also have the Lee 2nd Manual and the Hodgdon 2023 manual, neither of these have 5.56 loads. Also sign up for the XXL Reloading sight which does have several 5.56 loads but it still does not have all the loads I am looking for. Any thoughts guys?

 

[canebreaker]

Sizing them to 223 instead of 556.

 

[Neil Andrew]

A 5.56 NATO is a 223 Rem at higher pressures. The 5.56 is a military round at 62k psi max, the 223 is a civilian round at 55k psi max. The brass for each is basically the same. You can shoot a 223 round in a 5.56 gun, but you should NOT shoot a 5.56 round in a 223 gun!

 

[canebreaker]

I've known that for years. Been loading 223's for 11 years.
Where does the 556 get more pressure over a 223? I know, wanting to know if you know.

 

[Neil Andrew]

A more powder load

 

[canebreaker]

Nope.
A 556 will shoot in a 223, you'll have to manually eject the case. The neck gets hung up.
The neck is longer, more area to compress the bullet.
In checking case length of 223 very few cases were over 1.760. I found more cases between 1.733 to 1.745. 556 boxer cases were always beyond 1.760. A few up to 1.776.
I found data for 556 once, it matched 223. No matter of style or weight of bullet they all matched.
On another state website a member trimmed 556 cases to 1.760. He gained a little more pressure. He was going to try trimmed cases at 1.765, I got booted and never went to that site again.

 

[rodneygt]

Isn’t part of the pressure difference that a .223 chamber is cut differently than a .556 chamber?

 

[Neil Andrew]

I have no idea where you are getting your information from, but:
1st - Why would you shoot a 5.56 round in a 223 chambered gun after everything that has been published by powder & ammo makers?
2nd - I have seen where the max load was exactly the for both loads, but look at the fill rate of that powder. You will find that it is not a very dense powder.
3rd - If you don't trim the cases from time to time they will lengthen. Brass does flow!
4th - Both cases have a case capacity of 28.8 grains of water (1.87 cubic cm).

 

[Neil Andrew]

Also go to this link and it explains what rodneygt was saying!

What is the difference between 5.56 NATO and 223 Rem ammunition? - Hornady Law Enforcement

Differences between the two are small but can have a large impact on performance, safety and weapon function. The first difference is the higher pressure level of the 5.56 NATO cartridge which runs at approximately 58,000 psi. A 223 Remington is loade...

www.hornadyle.com

 

[Redlick83]

Its all due to the throat as there is no real external difference in ammo. As mentioned it the article above its just a higher pressure loading for the 556. Similar to 6.8spc and 6.8 spc Spec-ii its all about the throat and in 6.8 case lead angle as well.

 

[Neil Andrew]

Thanks, again does anybody know of a good site or source for 5.56 load data?

 

[Redlick83]

Hornady 9th edition 5.56 Nato loads. Also has 223 service rifle loads and 223 Remington loads as well.

 

[Redlick83]

For comparison this is the 223 service rifle load data. It doesn’t go below 68gr.

223 Rem doesn’t go above 60gr so it seems hornady separated these based off of common twist rates. Their 223rem loads are 1/12 twist, the service rifle loads are 1/9 twist and 556 loads are 1/7 twist.