.223 rem vs. 5.56 nato
what exactly are the differences between these two rounds and what effects are there in cup pressures and accuracy when using either/or in each respected chambers ? are all nato barrels stamped?and are these differences similar pertaining to .308 win vs. 7.62 nato?you can buy .223 and .308 factory reloads that have nato headstamped brass and rarely in the stores do you see 5.56 or 7.62 nato? many argue no difference,though the chamber specs are different? thanks and the 1911 still rules!
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http://forums.gunbroker.com/topic.asp?TOPIC_ID=482169
Neal
EDIT: Maybe the best answer to the OP's questions is: "It depends."
If you are talking about an AR, many barrels are not caliber marked. Colt's certainly aren't marked, although the lower receiver is usually marked .223 on the civilian rifles (I don't know about the M16). (And shipping labels are marked ".223/5.56mm".) We know that the same chamber was used on all their standard rifles, which were designed for 5.56mm. Obviously there is no problem with firing either round in any Colt. As Nononsense pointed out, there is a wide variation in chambers used by other makers, but I don't know of any with caliber restrictions.
Some .223 sporting rifles, especially bolt actions, may have trouble chambering certain rounds & caution should be used.
7.62mm/.308 WIN is a completely different story; standard loadings for .308 produce substantially higher pressures than 7.62mm, so, again, caution must be used & it depends upon the rifle.0 -
general rule of thumb AND SOMEONE PLEASE CORRECT ME IF I'M WRONG.
OK to fire .223 Remington in 5.56mm marked guns
NOT ok to fire 5.56mm in .223 Remington marked guns
OK to fire 7.62 NATO in .308 Winchester marked guns
NOT ok to fire .308 Winchester in 7.62 NATO marked guns
There are exceptions, I'm sure, but that's how I do it, and have had zero probs, ever.0 -
general rule of thumb AND SOMEONE PLEASE CORRECT ME IF I'M WRONG.
OK to fire .223 Remington in 5.56mm marked guns
NOT ok to fire 5.56mm in .223 Remington marked guns
OK to fire 7.62 NATO in .308 Winchester marked guns
NOT ok to fire .308 Winchester in 7.62 NATO marked guns
There are exceptions, I'm sure, but that's how I do it, and have had zero probs, ever.
I have a 581 series Mini-14 that cycles the 5.56 ammo as well as the .23.0 -
I have a Rem 700 VS in .223 and I shoot only .223 in it.
I have several ARs and several Mini-14s that I shoot both .223 & 5.56 ammo in and have never had any problems in many thousands of rounds.0 -
Here's another "correct me if I'm wrong" but here's how I've always thought of it.
A round labeled 5.56 NATO should be loaded/manufactured to military/NATO specs where a .223 Remington, more often than not, isn't.
The NATO round must function every time in an M16 for instance. If you put a .223 Rem round in an M16/AR that has been loaded with a 36 grain Varmint Grenade it may not cycle the action but it'll work fine in a bolt gun. Stuff like that.0 -
quote:Originally posted by idahoducker
Here's another "correct me if I'm wrong" but here's how I've always thought of it.
A round labeled 5.56 NATO should be loaded/manufactured to military/NATO specs where a .223 Remington, more often than not, isn't.
The NATO round must function every time in an M16 for instance. If you put a .223 Rem round in an M16/AR that has been loaded with a 36 grain Varmint Grenade it may not cycle the action but it'll work fine in a bolt gun. Stuff like that.
Although this may be the case, it is not the safety reason. 5.56 NATO ammunition is a higher pressure than .223. .308 is a higher pressure than 7.62. This is why the "rule of thumb" that Loaf posted works out.0 -
quote:Originally posted by PBJloaf
general rule of thumb AND SOMEONE PLEASE CORRECT ME IF I'M WRONG.
OK to fire .223 Remington in 5.56mm marked guns
NOT ok to fire 5.56mm in .223 Remington marked guns
OK to fire 7.62 NATO in .308 Winchester marked guns
NOT ok to fire .308 Winchester in 7.62 NATO marked guns
There are exceptions, I'm sure, but that's how I do it, and have had zero probs, ever.
That's about right.
Now my understanding is that in practice, despite the different spec, many of the commercial .308 loads aren't loaded any hotter than 7.62x51 NATO.
Some guns labelled .223 can handle the military type 5.56 ammo just fine.
This note from Federal ammo succinctly summarizes the difference:
http://le.atk.com/pdf/223VS556.pdf0 -
Does anyone know the engineering logic at Winchester when they slightly modified the military 7.62mm round into what they called the .308 Winchester? Why did they mess with it? Backing up the calander to the inception of the .30-06, that round was a military round and the civilian companies simply produced US military grade .30-06 ammo and it was readily accepted into civilian service. But then comes the 7.62mm NATO round and Winchester just had to mess with it and produced the .308 Win.
So to, when the military was gearing up for the .22 caliber class of ammunition, they basically started with the .222 Remington, tweaked it a little, and came up with the 5.56 military round. And then, once again, the civilian engineers messed with it and came up with the .223 Remington. [?] What don't I understand about this seemingly unnecessary messing around with a millimeter here and there, and slightly different loadings? The .30-06 was just fine for the Mil and Civ folks, why the messing around with the later rounds?0 -
There is a site called The Gun Zone
http://www.thegunzone.com/556faq.html
with frequently asked questions regarding stuff like this, which provide pretty detailed information and measurements.
The link above is as regards the 5.56mm versus the caliber .223 rounds. They go into this in depth. You can drill back and down at that site and see similar information on the 7.62 versus the caliber .308 rounds.
There's another site out there called Steve's Pages that also offers similar information0 -
Trefer- Winchester created and marketed .308 Winchester BEFORE the miltary created the 7.62 NATO. 0
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