Ak Guy
Member
I just read an article in Guns Mag about not shooting 5.56 NATO in .223 chambers. My AR is marked as "5.56 mm" , but is that the same as "5.56 NATO" ?
5.56 vs 5.56 NATO ?
- Thread starter Ak Guy
- Start date
- Status
Sunray
Member
Yes. Before there was an Internet, the .223 Rem and 5.56 NATO were the same thing. Ditto for .308 Win and 7.62 NATO. Millions of rounds of surplus ammo(there was lots of it long ago), in both chamberings, got fired out of rifles, both milsurp and civilian, with no fuss.
There are minor dimensional differences between .223 Rem and 5.56 NATO, but generally not enough to create issues.
Most rifle manufacturers today recognize that their .223 chambers will likely seen 5.56 NATO rounds at some point and allow for the difference in their chamber cuts.
Most rifle manufacturers today recognize that their .223 chambers will likely seen 5.56 NATO rounds at some point and allow for the difference in their chamber cuts.
ugaarguy
Member
- Joined
- Mar 19, 2006
- Messages
- 13,828
While this is true there are still manufacturers cutting chambers to the true .223 Spec, and now ammo like Black Hills 5.56 77gr OTM - AKA Mk262 Mod 1 - is fairly available. Mk 262 and similar 5.56 loads are running on the hot side pressure wise in 5.56 chambers. I'd not want to shoot it in a .223 Rem chamber with the shorter leade and resultant pressure spike.
rcmodel
Member in memoriam
I'd say it is.
They don't call anything else 5.56 mm except 5.56 NATO.
rc
They don't call anything else 5.56 mm except 5.56 NATO.
rc
wally
Member
^^^ This.
I'll worry about it when someone can show me a documented instance of an actual problem from shooting 5.56 in a .223 or vice-versa.
Tea leaf reading of "shiny marks" on a case head don't cut it!
Ak Guy
Member
thank you Walkalong and rcmodel......you understood my question exactly !
So just to re-state it..."5.56mm" and "5.56 NATO" are synonomous w/ regard to chamberings......right ?
So just to re-state it..."5.56mm" and "5.56 NATO" are synonomous w/ regard to chamberings......right ?
rcmodel
Member in memoriam
It's right in my book.
Nobody would mark it 5.56 mm unless they didn't own the 5.56 NATO stamp.
Or ran out of room to stamp it.
BTW:
The original .223 / military 5.56mm pressure problem dates back to the 1960's when there really were pressure problems firing stolen military 5.56 in tight match chambered .223 Remington 40x bench-rest & varmint rifles.
Also, there were some SAKO Vixen varmint rifles imported then with tight .223" bores, and tighter varmint rifle chambers.
Blown primers on those two guns lead to the present day warnings.
Personally, I do not believe any manufacture in this day & age of 'sue your socks off' at the drop of a hat would chamber a .223 rifle that suddenly becomes dangerous if you happened to buy a box of 5.56 NATO at Walmart and shot it in a .223.
Nobody reads the warnings in the owners manuals.
And don't understand them if they do!
rc
Nobody would mark it 5.56 mm unless they didn't own the 5.56 NATO stamp.
Or ran out of room to stamp it.
BTW:
The original .223 / military 5.56mm pressure problem dates back to the 1960's when there really were pressure problems firing stolen military 5.56 in tight match chambered .223 Remington 40x bench-rest & varmint rifles.
Also, there were some SAKO Vixen varmint rifles imported then with tight .223" bores, and tighter varmint rifle chambers.
Blown primers on those two guns lead to the present day warnings.
Personally, I do not believe any manufacture in this day & age of 'sue your socks off' at the drop of a hat would chamber a .223 rifle that suddenly becomes dangerous if you happened to buy a box of 5.56 NATO at Walmart and shot it in a .223.
Nobody reads the warnings in the owners manuals.
And don't understand them if they do!
rc
Last edited:
- Status