Nosler Data 223/5.56

[steve4102]

Nosler #7 has data for both the 223 and the 5.56.

The 223 data page list heavy bullets under the 5.56 name and also lists the same heavy bullet data under it's own 5.56 section(page).

Does Nosler test the 5.56 data at higher pressures than their 223 data and if so, why would this higher pressure date be listed on the 223 data page?

 

[RiverRider]

There seems to be a lot of conflicting info out there.

I've done a lot of searching and reading on the subject, and based on what I've been exposed to, here are the "facts" pertaining to M192 and M855 ammo:

- if you see NATO specs, pressure is given as 62000 psi
- NATO pressure testing is basically the same as the CIP method
- US military specs the ammo at 55000 psi
- US military pressure testing is basically the same as SAAMI pressure testing

My conclusion is that, at least as far as the .223/5.56 cartridge goes, 55000 psi using SAAMI methods is equivalent to 62000 psi as measured via CIP methods. I do NOT believe that .223/5.56 ammo should be loaded hotter for use in an AR15 whether it has the 5.56 chamber or not.

All that pertains to older information, of course. Later versions of 5.56 have been specced to somewhat higher pressures. M855A1 is the example. It is supposedly considerably hotter than 55000 psi, but I'm not sure that exact numbers have been revealed. The highest pressure spec I've seen published for US military 5.56 is a little over 58000 psi using the measurement very similar to the SAAMI method.

In my opinion, all the published liading data for 5.56 that shows to run 62000 psi is suspect.

 

[steve4102]

There seems to be a lot of conflicting info out there.

I've done a lot of searching and reading on the subject, and based on what I've been exposed to, here are the "facts" pertaining to M192 and M855 ammo:

- if you see NATO specs, pressure is given as 62000 psi
- NATO pressure testing is basically the same as the CIP method
- US military specs the ammo at 55000 psi
- US military pressure testing is basically the same as SAAMI pressure testing

My conclusion is that, at least as far as the .223/5.56 cartridge goes, 55000 psi using SAAMI methods is equivalent to 62000 psi as measured via CIP methods. I do NOT believe that .223/5.56 ammo should be loaded hotter for use in an AR15 whether it has the 5.56 chamber or not.

All that pertains to older information, of course. Later versions of 5.56 have been specced to somewhat higher pressures. M855A1 is the example. It is supposedly considerably hotter than 55000 psi, but I'm not sure that exact numbers have been revealed. The highest pressure spec I've seen published for US military 5.56 is a little over 58000 psi using the measurement very similar to the SAAMI method.

In my opinion, all the published liading data for 5.56 that shows to run 62000 psi is suspect.

I agree completely. It is a myth that 5.56 is loaded to 62K using SAAMI testing methods as 62K CIP method will equate to 55K in SAAMI method.

That is Why I posted the question above.

Nosler list both 223 and 5.56 load data and they are even on the same page.

I assume that Nosler is using SAAMI pressure testing procedures and I am wondering if their 5.56 data is tested at 55K psi or 62K psi?

 

[RiverRider]

I see what you're saying now. I don't have a Nosler manual, but in the online data it appears that they list the very same charges for .223 and 5.56. I would assume that the data is all 55000 psi since they would not list .223 loads above SAAMI pressures.

I have seen other manuals,though, where it appears that they list 5.56 data at 62000 psi and presumably measured via SAAMI methods because they are in fact hotter loads. I keep thinking Hornady has done this, but I don't have access to my manuals right now so I can't verify that. I believe QuickLOAD is set up this way, too, and I think it's not a good thing. I suppose I could be incorrect in my conclusions, but I haven't found authoritative information proving otherwise.

 

[steve4102]

, but in the online data it appears that they list the very same charges for .223 and 5.56.

Kinda.

If you click on Nosler online data for the 223 you will have the Heading 223 Rem for bullet weights from 34gr up to and including 64gr.

At 69-80gr although still under the 223 Rem data page, Nosler has the heading 5.56 Nato.

Is this 5.56 load data tested under the MAP of the 223 of 55K even though it is entitled 5.56 NATO?

If we leave the 223 data page and select 5.56 NATO we see the same 69-80gr bullet weights and the identical Data listed under the 223 Rem page???

Why the two different cartridges listed if they are the same SAAMI MAP?

If they are not the same pressure, why list the 5.56 under the 223 data page?

 

[RiverRider]

Thought I saw, but didn't...and NOW I see exactly what you're looking at. Strike TWO!

I'll just take the walk to first and make no assumptions. Maybe someone can give a real answer.

 

[steve4102]

Thought I saw, but didn't...and NOW I see exactly what you're looking at. Strike TWO!

I'll just take the walk to first and make no assumptions. Maybe someone can give a real answer.

Someone from Nosler would be appreciated, as this causes a lot of confusion with the 223 vs 5.56, as if we don't have enough confusion, myths and misconceptions already.

 

[Tjay]

There is a difference in the the leade between the 223 and 5.56 chambers. This is why they say to not shoot 5.56 ammo in a 223 chamber.

Also the tech note in the manual says 5.56 rifles have a 1-8 twist or faster which will stabilize bullets up to 80 gr. It notes that these loads can be used in the 223.

All of this is to say it looks like Noslers way of saying the 69 gr. and up bullets need a fast rate of twist.

 

[steve4102]

Thanks, all I had to do was read.