Hi everybody, thanks for letting me into the party.

To start I'm new to the forums here but I gotto say this is about the most complete shooting info outlet I've seen! you guys cover everything here... I appreciate all the knowledge you all share...

I have looked to see if any of my questions have alredy been asked here but I havn't seen anything recenty to answer my questions so I appologise in advance if this line of questions is getting old...

Now I've been handloading for 15 years or so and am pretty good at "what I know" I've had the same loads for years and found out what works for me and I dont usually change things...but when I do go outside of what I know I'm not to proud to ask for help...

I've loaded thousands of rounds of 223 but all with civilian brass...now I have the chance to reload the NATO version brass...

I am well aware of the issues with primer crimps and have a method for dealing with that...

I have taken a random sampling and weighed the nato brass versus the civi and its obvious that the Nato is a much heavier case.
I know that its supossed to have a thicker wall and therefore a smaller internal case volume...

I did a water weight sample of 30 cases and got an average of 30grains water weight...
I did the same 30 case average with civi brass and came up with 29.5 grain water weight... HUH...

I'm not that great with math to be honest, but this is nowhere near a 10% difference between the Nato and Civi?

I figured there would be a much bigger difference between the case volumes based on the difference in case weight (nato vs. civi)

AM I MISSING SOMETHING HERE??? i dont want to get FUBAR...

I made 10 test rounds of the nato rounds using
CCI small rifle primers
21grs of Hodgdon h322 (min starting load)
55gr winchester spbt

I was not able to chrono them but the loads fed perfectly thorough my probably somewhat loose GB mini-14...I inspected the spent cases for obvious signs of pressure problems and head stamp distortion and nothing? they seem to shoot great!

so after all this i'm inclined to rip off another thousand of them. But this is where I get nervous and say whoa! slow down and ask! you might be overlooking something...

The web is filled with horror stories about reloading Nato brass... after my test rounds I dont see why? There must be dozens of you out there that have reloaded 556x45... what are you all doing?

Thanks for the input...

Tim

The reason you hear of people getting into trouble, is when they use a max or near max .223 remington recipe in a 5.56 case, the 5.56 case is thicker, that leads to more pressure for a given load due to the reduction of case volume.

.223 remington is about 50k psi, the nato 5.56 is 60k psi.


so a 50k psi max load for .223 in a .556 could be over 60k psi easy, that will/has caused .223 guns to go poof.

Although GI brass in .308 and .30-06 does tend to be somewhat less capacious than commercial brass, I have found very little difference in .223 brass. Loads have generally been interchagable between GI brass (of various origins including foreign) and commercial R-P in a variety of rifles so chambered.

5.56 brass does NOT have less case capacity then civilian 223 brass as you found out in your testing.

From the experts at Sierra.

The conventional wisdom to reduce loads with military brass is familiar to most reloaders and is generally good advice. The rationale here is that the military cases tend to be somewhat thicker and heavier than their civilian counterparts, which in turn reduces capacity and raises pressures. This additional pressure normally requires a one or two grain reduction from the loads shown in most manuals or other data developed with commercial cases. While this is most often the situation with both 308 Winchester and 30-06 cases, it is less true with the 223 brass. We have found that military cases often have significantly more capacity than several brands of commercial brass. We have found that military cases often have significantly more capacity than several brands of commercial brass. Again, take the time to do a side-by-side comparison of the cases you are working with and adjust your load as needed. There may be no need for such a reduction with the 223. Know your components and keep them segregated accordingly.

Here is a good read on the 223 vs 5.56 case volume. Note the 223 has less case capacity than the 5.56.

http://www.6mmbr.com/223Rem.html

There is a big secret when comparing weight of brass vs water....that is the comparative volumes of one grain of brass vs one grain of water.

Water is only 1/8 the density of brass.
(density can also be referred to as specific gravity) It takes 8 grains of water to take up as much space as 1 grain of brass.

FWIW - Powder has about (notice I said about or approximately so it is only a rule of thumb) the same specific gravity as water - about 1 gr per cc.

Good article steeve4102, thankyou.

ok so I see one main difference is the longer throat in the 556x45...

I'm slowly drawing a picture here...

does that mean that a rifle chambered in .223 has a shorter throat (free bore) and when you run the longer 556x45 the neck of the brass would be to close to the start of the rifeling?

also if trimming the brass to a consistant length wouldn't it bring it back to the .223 throat length?

if I understand this potential issue correctly you can over pressure a chamber because the brass is fully engaged into the rifleing causing additional crimp in essense on a shorter throat .223 chamber?

Hope that makes sense, just trying to understand the mechanics of this.

Tim

The bullet gets closer to the rifleing in the shorter throat casuing pressure problems with longer heavier bullets. Chambers and necks are nearly identical, Mil Spec 5.56 chamber is a tad longer (allowing a little more build up to accumulate between cleaning)but the outer dimmensions of the .223 and 5.56 case are the same. A longer heavier bullet will be in the rifling causing pressure spikes.

A good comparrison of the chambers is available here http://ar15barrels.com/data/223-556.pdf based off of the different reamers.

Thats interesting Sam...

All of this tells me that its probably not a good idea to run 556x45 or nato (factory) loads in a .223 chamber rifle... but really if you are just using 556 brass to reload .223 its fine.

the bullet weight and length is the main issue causing OP problems... at least thats my take after reading this...using standard 55 gr civi bullets will not pose a problem.

I'm going to procede forward tonight with a hundred or so rounds keeping the starting load 21 grains of 322. I will test fire with my mini-14 gb this weekend...

I will post my results and observations but based on my first 5 I think there gonna shoot and cycle just like every other .223 I've cooked up.

still if I'm missing the big picture let me know.

Thanks

I've shot thousands of rounds of LC military brass through my Remington 700 .223 with some high stepping loads with no ill effects. I've used almost exclusively the 40g Nosler BT bullet and it is not seated into the lands.

I would think the seating depth of the bullet would have more effect on the pressure curve than whether or not it's a .556 case of a .223 case. The cases came with the primer pocket reamed and I've reamed the flash hole and camfered the mouth and gone down the road with no problems. Jamming the bullet into the lands may/maynot increase accuracy but can lead to pressure spikes.

As you already know, just proceed slowly with your own shooter by starting with smaller powder charges and move upward until you arrive at the sweet spot for you. I just don't think the mystery is there with these military cases as it once MIGHT have been. Just my opinion, but I like it.

I'd work up, loading 5 or 10 of a given weight of powder before doing a large batch. Sierra has a starting load of 22.5 of H322 at 2700 FPS for 55 grain bullets in an AR. Should be similar in a Mini-14. They list 24.3 as a max.

Here's a comparison picture of the throats of 5.56 NATO and 223 throats.

quote:

Originally posted by Fjold:
Here's a comparison picture of the throats of 5.56 NATO and 223 throats.

Interesting and informative photos, thanks

quote:

I'm going to procede forward tonight with a hundred or so rounds keeping the starting load 21 grains of 322. I will test fire with my mini-14 gb this weekend...

Your 21gr load is below min according to Sierra, Speer and the "Start" load according to Hodgdon. I would not load more than a few at that charge as it may not cycle the action of your Mini-14.

BTW you are aware that your Mini-14 has a 5.56 chamber and will safely accept 5.56 Ammo?

quote:

Originally posted by Shoedumup:
Good article steeve4102, thankyou.

ok so I see one main difference is the longer throat in the 556x45...

I'm slowly drawing a picture here...

does that mean that a rifle chambered in .223 has a shorter throat (free bore) and when you run the longer 5.56x45 the neck of the brass would be to close to the start of the rifeling?

also if trimming the brass to a consistant length wouldn't it bring it back to the .223 throat length?

if I understand this potential issue correctly you can over pressure a chamber because the brass is fully engaged into the rifleing causing additional crimp in essense on a shorter throat .223 chamber?

Hope that makes sense, just trying to understand the mechanics of this.

Tim

The external brass dimensions are identical for all practical purposes. It is the bullet depth that you have to worry about. NATO ammunition can jam the bullet into the rifling, running the already higher NATO perssures too high. Pierced primers and worse can happen.

So to summarize, firing surplus 5.56 NATO ammunition or NATO spec ammo in a 223 Remington chamber is a no-no but reloading 5.56 NATO cases with 223 Winchester data and COL is OK in a 223 chamber. Firing 223 Remington in a 5.56 chamber is safe but the extra freebore can degrade accuracy. The 223 Wylde chamber addresses the conflicts and that's why you see it on so many commercial AR rifles.

Here's a good summary from Federal Ammunition:

223 vs 5.56

You can deduce correctly that there is a lot of production 5.56 sold to LEO that is NOT suitable for 223 rifles. My buddy just lucked into about 5-6000 rounds of spent brass from an LEO qualification event. All of that ammo was NATO spec but we will load it all for our 223 rifles.

quote:

It is the bullet depth that you have to worry about. NATO ammunition can jam the bullet into the rifling,

This is incorrect. The 5.56 and the 223 share the same Max COAL, OAL 2.260 as both must fit the AR Mag. If Nato ammo was longer than 223 ammo it would be rendered useless in a AR-15 as it would have to be loaded single shot.

There is no mil spec Nato 5.56 ammo that will pig jam into the lands of an AR rifle chambered in 223 or 5.56.

I'll defer to your opinion but I wasn't talking about COL per se, more the datum line of the bullet. I've had the unlucky experience of having NATO green tip jam in a 223 bolt gun. Maybe it was a one-off bad chamber.

quote:

Originally posted by steve4102:

quote:

I'm going to procede forward tonight with a hundred or so rounds keeping the starting load 21 grains of 322. I will test fire with my mini-14 gb this weekend...

Your 21gr load is below min according to Sierra, Speer and the "Start" load according to Hodgdon. I would not load more than a few at that charge as it may not cycle the action of your Mini-14.

BTW you are aware that your Mini-14 has a 5.56 chamber and will safely accept 5.56 Ammo?

thanks for looking out for me Steve but I am useing Hodgsdon 322 that lists a starting load of 21grs for 55gr bullet...? the 335 powder lists a starting load of 23grs so I agree with you there if I was using that powder...I think I'm good with that # but as always if I'm wrong please dont hesitate to kick me in the ARSE!

Also i wasn't really sure about my Mini-14. I suspected that it might be. Now, is that because it is a GB model? would a todays version mini-14 be a 223 chamber...

I had to move onto 9mm reloads to get ready for last sundays shoot so I have not made up any more of these 556 brass rounds yet...I will keep you posted when I do.

BTW picked up my new 1911 RO tonight...I'm in love with my gun! sounds like an episode of that "taboo" show... Its my first 1911 I've wanted one for 25 years...FINALLY!

Here's a picture of the actual chambers cutaway:

quote:

Also i wasn't really sure about my Mini-14. I suspected that it might be. Now, is that because it is a GB model? would a todays version mini-14 be a 223 chamber...

All Mini-14 except the "Target" model have 5.56 chambers.