5.56mm X 45mm NATO Spec

[Fronty Owner]

Anyone reload to NATO pressures?
What are some trusted resources? My Lymans book only lists .223 remington.

[Adaminak]

Never bothered to find it, but I do know the NATO case is internally smaller and you can't use standard .223 recipes...I'll do a bit of digging and see if I can find anything.

[Fronty Owner]

NATO and SAAMI measure pressures differently and NATO allows a higher pressure and different pressure curve. Im not so much trying to replicate NATO performance. there are plenty of recipes on the web for that. Im looking more along the lines of recipes to push commercial powders to NATO pressures.

[annabelle]

Can't find any source that gives the internal pressures for commercial powders in a NATO case. Only velocities which I'm sure you already know.

[Fronty Owner]

thats kinda what I have run into.

Oh well. My tail is tired now. Loaded up 125 rounds of .223 and 90 rounds of 7mm Rem Mag.
I just have 260 more brass in .223 to clean up and prep.

[tightgroup]

...but I do know the NATO case is internally smaller and you can't use standard .223 recipes.

Do you have some data to back up this statement? I have been reloading 223/5.56 for a long time and I see variations in both commercial and military cases. My understanding is that the cases are basically the same but that 5.56 is loaded to higher pressures.

The biggest issue I see is the chamber dimension of the gun that you are reloading for. Be very careful as I have seen barrels that are marked 5.56 but are on the small side. This is especially true on the lower cost carbines.

As always with reloading, it is best to start with a safe load and work up in increments until you start to see signs of over pressure. Try to stay with the same brand and lot of brass when you do this.

[Fronty Owner]

Ive shot nato stamped lake city factory loads and haven't seen any over pressure signs.
Im using a Model 1 Sales upper kit.

[annabelle]

The NATO case is slightly thicker therefore giving it a reduced case volume and greater pressure with a given load. Goggle it for more info.

[annabelle]

Do you have some data to back up this statement? I have been reloading 223/5.56 for a long time and I see variations in both commercial and military cases. My understanding is that the cases are basically the same but that 5.56 is loaded to higher pressures.

The biggest issue I see is the chamber dimension of the gun that you are reloading for. Be very careful as I have seen barrels that are marked 5.56 but are on the small side. This is especially true on the lower cost carbines.

As always with reloading, it is best to start with a safe load and work up in increments until you start to see signs of over pressure. Try to stay with the same brand and lot of brass when you do this.

www.6mmbr.com/223rem.html

[tightgroup]

Ive shot nato stamped lake city factory loads and haven't seen any over pressure signs.
Im using a Model 1 Sales upper kit.
Very good. My experience with being a range officer on a public range has shown that this is not always the case. Hence the warning. ;)

This last summer on a hot day we had a guy blowing primers out of factory Federal XM193 in his DPMS with a barrel marked 5.56.

The NATO case is slightly thicker therefore giving it a reduced case volume and greater pressure with a given load. Goggle it for more info.

I have seen that statement on the Internet before, and I think Wikipedia even has some information to that effect but my personal experience is that they all vary so use caution.

[Fronty Owner]

Its been my experience reloading with 26 gr of Varget, the variation in cases manufacturer is about the same as the difference between commercial and NATO cases. NATO will be typically more full than commercial, but Ive had commercial as full as NATO with the same weight of powder.

http://i74.photobucket.com/albums/i245/FrontyOwner/firearms/100_2736.jpg
I got a few projectiles to play with now... Also, gonna find out in my 1 in 9 twist will stabalize a 68 gr bullet.

[annabelle]

My Hodgdon's manual does have CPU listed for each powder, and wt. of powder. However it is a 92 addition and does not show the NATO round. You may be able to get a newer manual and compare the two case pressures.