I ran into quite a large number of once fired brass at the range I go to for free and took it home. Upon further inspection, I know that the brass is all Lake City brass (LC headstamp) with various numbers to the right (02, 05, 06) and the NATO cross on the top with a dot next to it.

My question is, since Googleing this hasn't turned up any definite answers, is this 5.56 or .223 brass? I know you can use them both in a 5.56 rifle, but for load development, it matters.

Anyone know for certain?

Thanks

Quoted: I ran into quite a large number of once fired brass at the range I go to for free and took it home. Upon further inspection, I know that the brass is all Lake City brass (LC headstamp) with various numbers to the right (02, 05, 06) and the NATO cross on the top with a dot next to it. My question is, since Googleing this hasn't turned up any definite answers, is this 5.56 or .223 brass? I know you can use them both in a 5.56 rifle, but for load development, it matters. Anyone know for certain? Thanks

5.56x45mm NATO vs .223 Remington

Which do you think is "NATO spec" ?

Quoted: Quoted: I ran into quite a large number of once fired brass at the range I go to for free and took it home. Upon further inspection, I know that the brass is all Lake City brass (LC headstamp) with various numbers to the right (02, 05, 06) and the NATO cross on the top with a dot next to it. My question is, since Googleing this hasn't turned up any definite answers, is this 5.56 or .223 brass? I know you can use them both in a 5.56 rifle, but for load development, it matters. Anyone know for certain? Thanks 5.56x45mm NATO vs .223 Remington Which do you think is "NATO spec" ?

Thread over.

Quoted:  I know you can use them both in a 5.56 rifle, but for load development, it matters. Thanks

How so?

Quoted: Quoted:  I know you can use them both in a 5.56 rifle, but for load development, it matters. Thanks How so?

Mil brass has thicker walls, which means less powder / more pressure versus thinner walled .223 cases.  Thats the theory anyway.

Quoted: Quoted: I ran into quite a large number of once fired brass at the range I go to for free and took it home. Upon further inspection, I know that the brass is all Lake City brass (LC headstamp) with various numbers to the right (02, 05, 06) and the NATO cross on the top with a dot next to it. My question is, since Googleing this hasn't turned up any definite answers, is this 5.56 or .223 brass? I know you can use them both in a 5.56 rifle, but for load development, it matters. Anyone know for certain? Thanks 5.56x45mm NATO vs .223 Remington Which do you think is "NATO spec" ?

Pretty much what I thought - but in reloading, guessing gets your rifle blown up. Plus I had read threads and pages where people have mentioned that a NATO cross doesn't mean they are within the same spec's as the US 5.56 cartridges, some say certain factories are using NATO stamped brass but it isn't, etc. Too much garbage out there to make a guess on when the end result will be 5 inches from my face.

As far as 5.56 vs .223 in reloading, the 5.56 has less case volume due to thicker walls. The same loads in both will give considerable differences in the pressures. If you are loading a "hot" .223 charge and put that same charge into the 5.56 case, the pressures will be unsafe at best.

Quoted: Quoted: Quoted:  I know you can use them both in a 5.56 rifle, but for load development, it matters. Thanks How so? Mil brass has thicker walls, which means less powder / more pressure versus thinner walled .223 cases.  Thats the theory anyway.

With regard to 5.56mm/223 Remington that is completely false.

Quoted: Quoted: Quoted: I ran into quite a large number of once fired brass at the range I go to for free and took it home. Upon further inspection, I know that the brass is all Lake City brass (LC headstamp) with various numbers to the right (02, 05, 06) and the NATO cross on the top with a dot next to it. My question is, since Googleing this hasn't turned up any definite answers, is this 5.56 or .223 brass? I know you can use them both in a 5.56 rifle, but for load development, it matters. Anyone know for certain? Thanks 5.56x45mm NATO vs .223 Remington Which do you think is "NATO spec" ? Pretty much what I thought - but in reloading, guessing gets your rifle blown up. Plus I had read threads and pages where people have mentioned that a NATO cross doesn't mean they are within the same spec's as the US 5.56 cartridges, some say certain factories are using NATO stamped brass but it isn't, etc. Too much garbage out there to make a guess on when the end result will be 5 inches from my face. As far as 5.56 vs .223 in reloading, the 5.56 has less case volume due to thicker walls. The same loads in both will give considerable differences in the pressures. If you are loading a "hot" .223 charge and put that same charge into the 5.56 case, the pressures will be unsafe at best.

As I stated above, this is false.  It's an urban myth that just won't die.

I've measured case capacities for both .223 Remington and 5.56 NATO, the difference is less than .1 gr. of water.

I have bought Federal 55gr or 60gr, whatever it was that was soft point regular old hunting ammo straight from walmart and it was nickle plated brass with LC and nato markings on it but it wasnt 5.56 ammo so no just because it has the nato markings doesnt mean its true nato spec 5.56. Same with the federal 50gr JHP value packs, half of its marked FC half is LC nato marked.