AR Question

[RepublicanMan]

Ok gang........Santa was REAL nice to me, he even came a little early in the form of a slightly used (150 rds max) Colt MT6700 Target Match Competetion HBAR rifle for $555.
Here's my question.....the barrel is stamped CMP 5.56 NATO / 1/9 HBAR. I have heard two stories regarding Colts civilian model ARs concerning ammo. I have been using XM193 Federal / Lake City. This is military spec ammo.....is that ok or do I need to stick with civilian .223 such as Black Hills etc???

 

[Duke of Lawnchair]

If the barrel is marked 5.56 NATO, then it SHOULD be chambered for the NATO cartridge. You've been running the XM193 through that gun and it should be fine.

Mil-spec ammo through a mil-spec chamber is fine.

Jim

 

[ny32182]

I concur.. if the barrel is stamped 5.56, you should be fine to use mil spec ammo all day long.

 

[go8dalejr]

Yeah, from what I have seen it is ok to use either 5.56 or 223 in a 5.56
chamber just not 5.56 in a 223 chamber. Merry christmas

 

[RepublicanMan]

Great, thanks for the replies guys.

Merry Christmas!!!!!!

I'm goin' shootin'

 

[Coltdriver]

The 223 Remington was adapted by the US military in 1964 as the 5.56 NATO.

What is the difference? They are the same cartridge.

The mil spec ammo is crimped but it is a .224 bullet.

Where is the problem??

 

[Quintin Likely]

It's not so much the diamensions of the .223 vs 5.56 NATO, although they are slightly different (but not different enough to matter to the average joe), it's more of the pressures they operate at. 5.56 NATO is loaded hotter than most civvie .223 loads are.

Lots of good info re. ARs and the ammo: www.ammo-oracle.com

 

[Duke of Lawnchair]

The .223Rem and 5.56NATO are not the same cartridge nor are they the same chamber.

.223Rem throats are shorter than it's 5.56NATO counterpart. As a rule of thumb, it's safe to shoot a .223Rem in a 5.56NATO chamber. However, if you shoot a 5.56NATO cartridge in a .223Rem chamber, you run the risk of higher chamber pressure. A lot of shooters run the 5.56NATO through a .223 tube without any catastrophic side effects. I'm just a little anal and wouldn't do that myself.

Jim

 

[Coltdriver]

Well not to get into an argument with you but I just pulled some 5.56 Winchester out of a box and it mic'd out identical in every dimension to my .223 brass that I reload with.

The only differences I have ever heard of between 5.56 NATO and .223 Remington is that the NATO ammo is usually crimped to put up with the abuse of full auto fire, the primer pocket is usually crimped for the same reason and the brass is usually a little bit thicker. This means that if you are reloading that you must be a little extra careful about compressed loads.

Perhaps you have a source for your 5.56 NATO spec ammo? Mine is the Lyman 48th which discusses the rounds interchangeably.

 

[Duke of Lawnchair]

Coltdriver,

Most .223Rem case walls are generally not as thick as their 5.56NATO counterparts. This isn't always true.

Weigh a few.

Overall outer dimensions are the same.

Back in the day when I used to do my own reloading I had weighed a few on my buddy's scale. The 5.56NATOs came out a tad bit heavier.



winchester

Jim

 

[NevadaPistolero]

this is a question thats asked pretty often and most people get it wrong..there is a difference...read the stats.... Ammo Oracle .......this will clear it up nicely for those who dont know or think they know.

 

[nemesis]

The 223 Remington was adapted by the US military in 1964 as the 5.56 NATO.

The 223 Remington hit the civilian market first but was "adapted" from the 5.56 NATO.

 

[Coltdriver]

I am always open to learning somthing new.

So the brass is dimensionally identical. Just the NATO rounds are loaded to a higher pressure and may have the military characteristics I mentioned above, but as you note, may not be thicker either!

I have an AR15, it has the 5.56 stamp on the barrel. But I am reloading for a .223 Ruger #3.

So this is timely information to discover. I don't plan on shooting anything but handloads through the ruger but I was not aware of the different chambering between the .223 and the M16/AR etc.

 

[Duke of Lawnchair]

Happy reloading!

I need to get back into that hobby.

Back in jr. high I had all the time in the world, but no money.
Fast forward into adulthood and now I have "some" money but no time.

Life is great...

Jim