5.56x45 ammo in a .223 cal. rifle?

[jeffc2x]

What's the difference in 5.56 and .223 ammo,anyting?I've been told not to shoot 5.56 through a .223 rifle.I've shot it in my model 10 ,no problems,and accurate.A tech at DPMS told a friend of mine the the chambers are different from a 5.56 to a .223,and pressure is higher on a 5.56.But he said the cases are different on the INSIDE of a 5.56 from a .223.My question is what does the inside of the case being different have anyting to do with the chambers?CAN ANYONE HELP? ???
JEFF

[GaCop]

Military brass is made thicker than commercial. Working pressure is higher for the military round and military throats are longer so using a military load in a shorter throat commercial chamber could raise pressure to an unacceptable level.

[rjtfroggy]

The 5.56 case is a military chambering, the cases are thicker and I believe develope more pressure than the civilian 223 chambering.
When reloading these cases the primer pocket needs to be reamed out so that a primer can be put in and the load needs to be adjusted because there isn't enough room for the powder charge with out compressing the load.
Most modern or up to date newer guns can probably handle the extra pressure but the "liability Lawyers" are looking to make a score on the end users who hurt themselves.
I believe the same warning goes along with the 7.62 and the 308 cartridge swaps.

[jeffc2x]

The 5.56 case is a military chambering, the cases are thicker and I believe develope more pressure than the civilian 223 chambering.
When reloading these cases the primer pocket needs to be reamed out so that a primer can be put in and the load needs to be adjusted because there isn't enough room for the powder charge with out compressing the load.
Most modern or up to date newer guns can probably handle the extra pressure but the "liability Lawyers" are looking to make a score on the end users who hurt themselves.
I believe the same warning goes along with the 7.62 and the 308 cartridge swaps.

I knew about the primer pockets and the thicker cases,but there is no difference in chambers?I know the reloading manuals say to reduce the load 10% when using military brass.So what I'm asking is if I use military brass with a safe amount of powder according to a reloading manual it won't hurt shooting 5.56 0ut of a .223 rifle?
Thanks for the replies
JEFF

[Jamie]

You should be good after the cases are resized and work up a load. I can tell you from experience though that it is completely possible to have over pressure when using 5.56 rounds in a .223 chamber. The differences are slight and according to books the pressure shouldn't be that much more but I have seen two different .223's (owned one) that would shoot max book loads of .223 rounds and never flatten a primer but shoot surplus 5.56 through them and they would pierce the primers.

[jeffc2x]

These are some South African 5.56 I bought from a guy just for plinking.They are Berden prime,so can't load them back.I've shot some Lake City ammo and bought military cases to reload.Thinking about just selling the SA ammo and get some 100 Fed .223 packs at Wally World.
THANKS JEFF

[tammons]

IF I remember right the 5.56 nato is about 5k hotter and the chamber is slightly bigger but thats what I was told.
I think the brass is the same dimensions except the 5.56 is thicker at the base.

Somebody told me a while back that the 5.56 no go gage was the same as the 5.56 nato go gage etc like it was a
couple of thousands longer.

[dolomite_supafly]

The throat is longer in the 5.56, other than that the chambers are identical or should be.

As far as the ammunition the 5.56 NATO has a higher working pressure than .223.

Here is all you ever wanted to know about the differences between 5.56 and 223 as well as variations of the 5.56.
http://razoreye.net/mirror/ammo-oracle/AR15_com_Ammo_Oracle_Mirror.htm

308 Winchester and 7.62x51 NATO are just the opposite. The NATO round has a lower operating pressure than the 308 Winchester. There are a lot of military rifles chambered in 7.62x51 that are warned against shooting commercial ammo in for safety reasons, HK and their clones come to mind but there are others as well.

Dolomite

[helotaxi]

There is also no truth to the rumor that military brass is thicker than .223 brass. In fact Lake City brass usually weighs less and has a larger internal volume than all commercial .223 brass.

The leade is longer with a shallower angle on the 5.56x45 chamber which allows a hotter load without spiking pressure.

Stick to .223 factory ammo or reloads within normal specs and you'll be fine. I've seen reports of 5.56 ammo fired in .223 chambers being as much as 17k CUP over pressure. That's over 33% which makes it higher than a proof load.

[jeffc2x]

There is also no truth to the rumor that military brass is thicker than .223 brass. In fact Lake City brass usually weighs less and has a larger internal volume than all commercial .223 brass.

The leade is longer with a shallower angle on the 5.56x45 chamber which allows a hotter load without spiking pressure.

Stick to .223 factory ammo or reloads within normal specs and you'll be fine. I've seen reports of 5.56 ammo fired in .223 chambers being as much as 17k CUP over pressure. That's over 33% which makes it higher than a proof load.

Ok,thanks.Anybody bought the 100 rd. packs of Federal.223 ammo at WM?I've been told it has a Lake City headstamp.
JEFF

[amadjuster]

I have read that SAAMI maximum is 50,000 PSI for .223 and NATO is 60,000 PSI for 5.56. Something about the length of the throat being longer in a NATO spec. AR-15.

[Fjold]

Here is a chamber comparison. The 5.56 chamber is on top and the 223 chamber is on the bottom. The pressure spec for the Nato cartridge is 62,000 PSI and the 223 pressure spec is 55,000 PSI. Shooting 5.56 spec ammo in a chamber designed for 223 pressures and with the shorter leade that the 223 has could result in dangerous pressures.
http://img.photobucket.com/albums/v214/Fjold/Chamber.jpg

[sha-ul]

are Savage factory chambers 223 or 556?

[helotaxi]

I've never seen anything other than semi-autos and autos in 5.56 NATO.

[amadjuster]

I have read that the Ruger Mini 14 has a 5.56 chamber and is safe for both. Everything else is marked either 5.56 or .223 Remington. My old Colt AR-15 was marked 5.56 Nato but I have seen other brands marked either way.

[sharpshooter]

If you do a chamber cast of a factory barrel, you will find it is neither....

[helotaxi]

They use a Wylde or one of the other hybrid chambers?

[darkker]

2 year-old thread that could use some honest updating.

Pressure data to back-up the claims.

http://www.luckygunner.com/labs/5-56-vs-223/