does anyone shoot .223 in their .556? AR

the farm store has a Rock river AR in stock, but it's 5.56

i.i.u.c.

one can go in the other
but one should not go in the other.

this is targets only shooting under 200 yards

the people at the farm store are very nice but I don't think they shoot much

All my ARs are 5.56 and half my ammo is .223. No issues.

At work, two of our rifles are 5.56 and the rest are .223 so I only buy .223 ammo at work.

Not an issue.

A 5.56 rifle can shoot both.

As stated, there is no problem shooting 223 Remington ammunition in a gun chambered for 5.56mm NATO. I have a 223 bolt action rifle and therefore usually purchase 223 ammunition for all my training.

quote:

Originally posted by bendable:
i.i.u.c.

one can go in the other
but one should not go in the other.

5.56 is a higher pressure (due to thicker case material), and should only go in barrels marked for 5.56 (or .223 WYLDE).

.223 is a thinner case, and lower pressure round that can be used in .223, 5.56, and .223 WYLDE barrels without issue.

5.56 chamber= 5.56 or .223



.223 chamber= .223 only

.223 Wylde chamber= .223 or 5.56

quote:

Originally posted by Gibb:
5.56 is a higher pressure

It’s conventional wisdom that 5.56 ammunition shouldn’t be fired in 223 chambers, but it’s not such a simple matter that the former has higher chamber pressures due to thicker case brass. There are Internet discussions that explain the things in detail for anyone who wants to know the actual reason(s) that have to do with the chamber and barrel design. That's why the 223 Wylde is safe for 5.56 ammunition: the chamber and leade are what are different, not that the barrel and other parts are beefed up to handle higher 5.56 pressures.

^^ Correct, it's just usually easier to remember 5.56 being the "+P equivalent" without getting lost in the technicalities.

Thanks for taking the time

Also note - Well, theoretically rounds meeting either spec (NATO 5.56x45 or SAAMI .223) will chamber and fire, the problem is that tolerances and some dimensions are different, meaning that firing a NATO round in a standard SAAMI chamber could result in a degree of danger to the shooter

Not the only difference. The specifications for military 5.56x45mm ammunition also call for primers with thick, heavy cup material, to make the cartridges less susceptible to slam-firing and firing out-of-battery when used in weapons with floating firing pins, such as the AR15/M16 rifle, and also when used in automatic weapons. Commercial .223 Remington ammunition has no such specification.

quote:

Originally posted by bendable:
does anyone shoot .223 in their .556? AR

the farm store has a Rock river AR in stock, but it's 5.56

i.i.u.c.

one can go in the other
but one should not go in the other.

this is targets only shooting under 200 yards

the people at the farm store are very nice but I don't think they shoot much

FYI - the chamber in Rock River AR's are typically (I will not say "all", but I've seen several that are not) not 5.56, despite the markings on their lowers.
I've seen this with multiple RR rifles and have personally used a Ned Christiansen Chamber Reamer to correct the issue.

If you get the RR rifle, suggest you do not use 5.56 unless/until you can check the chamber.

Or, get a rifle that's actually been built correctly.

Example: Primary Arms has been offering complete BCM "blem" lowers at $340 lately. They've been in/out stock over the past several weeks.
Add a BCM upper - several options available if you look in the right places, and you can have a quality/in-spec rifle for probably not too much more than the RR.

The RR rifle will also likely need a few additional things addressed, such as the following:
The gas key is likely not staked or not staked correctly. Additionally, the gas key screws are likely YFS (made in China garbage) and should be replaced.
The receiver end plate is likely not staked or not staked correctly and the castle nut is likely not torqued correctly.
And the barrel nut is likely not torqued correctly and also likely not installed with grease.

What's the farm store price on the RR rifle?

quote:

Originally posted by g4tx:
FYI - the chamber in Rock River AR's are typically (I will not say "all", but I've seen several that are not) not 5.56, despite the markings on their lowers.

Well... Lower receiver markings have no bearing on what the upper/barrel is chambered in anyway.

This goes beyond just .223 vs. 5.56. Any AR15 upper receiver can be used on any standard AR15 lower receiver. So the lower may say 5.56, but the upper that is currently installed is actually 9mm. Or 7.62x39. Or .22LR.

Always go off the markings on the barrel when determining what that AR is currently chambered in, not what is marked on the lower receiver. (Besides, many AR lower receivers nowadays simply say "Caliber: Multi" or something similar.)

Or in the case of a new complete factory AR, you can also go off the caliber that's noted on the packaging/label, instead of the lower receiver.

quote:

Originally posted by RogueJSK:

quote:

Originally posted by g4tx:
FYI - the chamber in Rock River AR's are typically (I will not say "all", but I've seen several that are not) not 5.56, despite the markings on their lowers.

Well... Lower receiver markings have no bearing on what the upper/barrel is chambered in anyway.

This goes beyond just .223 vs. 5.56. Any AR15 upper receiver can be used on any standard AR15 lower receiver. So the lower may say 5.56, but the upper that is currently installed is actually 9mm. Or 7.62x39. Or .22LR.

Always go off the markings on the barrel when determining what that AR is currently chambered in, not what is marked on the lower receiver. (Besides, many AR lower receivers nowadays simply say "Caliber: Multi" or something similar.)

Or in the case of a new complete factory AR, you can also go off the caliber that's noted on the packaging/label, instead of the lower receiver.

Well... the OP asked about a 5.56 RR rifle.
Lower receiver markings are kind of important when buying a complete factory rifle.

And I was addressing the specifics of what I've seen regarding complete RR rifles marked as 5.56 caliber.

quote:

Originally posted by g4tx:
And I was addressing the specifics of what I've seen regarding complete RR rifles marked as 5.56 caliber.

Marked 5.56 on the lower... Which is practically irrelevant.

What do these RR barrels say? .223 or 5.56?

What do the labels on these boxes say? .223 or 5.56?

If RR is selling them as .223 rifles, marking them .223 on the barrel, and putting .223 on the label, but using 5.56 lowers, that's not really an issue. (Not much more than just putting "Multi" on the lower.)

But if RR is marketing them as 5.56 rifles, marking the barrels as 5.56, and putting 5.56 on the label, but only cutting .223 chambers, that's a problem.

quote:

Originally posted by g4tx:

quote:

Originally posted by RogueJSK:

quote:

Originally posted by g4tx:
FYI - the chamber in Rock River AR's are typically (I will not say "all", but I've seen several that are not) not 5.56, despite the markings on their lowers.

Well... Lower receiver markings have no bearing on what the upper/barrel is chambered in anyway.

This goes beyond just .223 vs. 5.56. Any AR15 upper receiver can be used on any standard AR15 lower receiver. So the lower may say 5.56, but the upper that is currently installed is actually 9mm. Or 7.62x39. Or .22LR.

Always go off the markings on the barrel when determining what that AR is currently chambered in, not what is marked on the lower receiver. (Besides, many AR lower receivers nowadays simply say "Caliber: Multi" or something similar.)

Or in the case of a new complete factory AR, you can also go off the caliber that's noted on the packaging/label, instead of the lower receiver.

Well... the OP asked about a 5.56 RR rifle.
Lower receiver markings are kind of important when buying a complete factory rifle.

And I was addressing the specifics of what I've seen regarding complete RR rifles marked as 5.56 caliber.

So your detective skills revealed some RRA rifles marked 5.56 on the lower receiver are actually chambered for .223 Wylde? Ever bothered to check their website, looked at a brochure, read the end label on a factory box, or barrel stamp?

Have you ever seen ANY lower receiver marked .223 Wylde? When was the last time you ever saw a .223 Remington marked lower?

This message has been edited. Last edited by: SIG228,

Try and find a .223 barreled upper AR15 these days. Good luck. It can be done but you are searching far and wide for a .223 barrel, and paying extra for it.

Just shoot any .223 or 5.56 ammo you can find in your modern AR15 rifles.