.223 remington versus 5.56 x 45 mm NATO - is it safe to interchange???

guess_kto said:
:bsFlag:

5.56 in 223 is safe. 223 has more strict measurements, while 5.56 has more variations to measurements simply becase too many countries use and produce it. Therefore, to accomodate all the rounds, the limits are more flexible and throat is more flat to reduce presure (just in case)...
Click to expand...

WWIII gave a very good explanation a few posts above yours.

Basically, if you have a new .223 Bushmaster AR and you only use 5.56 in it, you'll be fine, but using 5.56 in an old bolt rifle with a match chamber may cause unsafe pressures and a catastrophic failure. This doesn't mean that it will explode, and I'd be surprised if it did; however, is it really worth risking it?

WWIII said:
In recent years manufacturers of both the 223 Rem and 5.56 Nato cartridges have pushed the envelope in cartridge development and design by making the projectiles heavier and longer thus requiring chambers be reamed with more leade for use of these new cartridges. Thus many of the newer 223/556 chamber designs mitigate many of these perceived potential pressure related safety issues.

Conversely SAAMI’s answer to this problem was to make a blanket statement deeming it an unsafe combination to use all 5.56 Nato in all 223 Rem chambers rather than to emphasize a procedure to effectively reduce the potential safety hazards associated with this issue.
Click to expand...
 
I have been ' taking that risk ' long before the internet came along , with all these supernovas being created by mixing and matching 308/762 and 223/556 on a hourly basis I have yet to see anything posted on youtube or live leak
 
jennis said:
I have been ' taking that risk ' long before the internet came along , with all these supernovas being created by mixing and matching 308/762 and 223/556 on a hourly basis I have yet to see anything posted on youtube or live leak
Click to expand...


Look harder jennis, it must be out there. The internet says so.
 
Wow, what a story. In MY guns I will shoot any in either as long as it chamber freely and I won't give it a second thought and have not for almost forty years. What you do with your guns however is entirely your responsibility! Reading this entire thread is more dangerous in my opinion!
 
Using the Same Caliber Ammo in non SAAMI form can cause a problem


If it wasnt for German engenieering I would not be here Today
IMG_2450.jpg

IMG_2444.jpg


in the End it's all about pressure
 
223 vrs 5.56

Ar180shooter said:
I'll explain it with smiles

:) = good
:( = bad

5.56 round in 5.56 chamber :)
.223 round in 5.56 chamber :)
.223 round in .223 chamber :)
5.56 round in .223 chamber :( - your #### may not fall off, but I wouldn't risk it!
Click to expand...

what planet! did you guys come from dose the miltary round have twice max.pressure as the 223 i think not !can a270 win be fired in a30/06 yes!,if it will chamber ,can you shoot a30/06 in a 270 no!,unless you force it in then you have a good chance of blowing the , barrel;because you are trying to force a.308 cal . down a.277 barrel .,can you shoot a280rem. in a30/06 again yes! ,if it will chamber but not the other way around l.ol.l.
 
I just got back from the range and fired 556 'nato' out of a 223 ( 700P ) and fired 7.62'nato' out of a 308 ( 700P ) and still have all my fingers and facial features.............again
 
I like how the 5.56mm's additional case thickness makes it unsafe for use in firearms chambered for .223, but the .308's thinner walls make it unsafe for firearms chambered for 7.62mm....:stirthepot2:
 
Again its been said before, the higher chamber pressure is an issue and "may" damage your rifle. Read the instructions in your firearms booklet. "USE ONLY AMMO SPECIFIED ON RIFLE RECIEVER"..Whats not to understand....It surely dos not say "USE ANY AMMO YOU WANT AT YOUR OWN RISK."
 
Ar180shooter said:
Sure!

:) = good
:( = bad

7.62 round in 7.62 chamber :)
.308 round in 7.62 chamber :)
.308 round in .308 chamber :)
7.62 round in .308 chamber :( - Again, your #### probably won't fall off, but when dealing with firearms, it's better to be safe than ####-less!

AFAIK, the 5.56 vs .223 and 7.62 vs .308 debates are essentially identical. Shooting a 7.62 cartridge in a .308 chamber should not cause a catastrophic failure; however, due to the slightly wider throat specifications in NATO chambers, firing either 7.62 or 5.56 NATO ammunition in .308 or .223 spec chambers will result in greater wear on the barrel throat and will reduce its service life.
Click to expand...
AR180 Shooter;

A quick thing: the 5.56/.223 and 7.62/.308 debates are NOT the same though to many they might be. FYI I used to engineer both of these weapons' systems (C1A1, C2A1, C3 & A1, as well as C7, C8, A1s, LSWs, C12, C13, etc) for DND and through contacts in DCRA did a lot of work on compatibility. SO...

5.56/.223 is as mentioned a throat configuration issue and with the stupidity of the US DOS we have all kinds of guns with markings that mean nothing compared to the chamber. The only safe way to deal with these things is to A. call the manufacturer (most of the serious companies build them to handle both - Colt in AR15A2s and more recent, Steyr AUG (only Scout and SBS are .223)) or B, get a chamber cast by a gunsmith and examine the shoulder diameters, leade, and shoulder to throat angles. So the previous smile gram is generally accurate BUT DOS has screwed things the last 2 years and I know for certain S&W refuses to answer the question. You can certainly get issues with 5.56 in a .223 chamber and if you are shooting tracer (Belgian L110, Canadian C78, US M856) you sure can have an issue as the bullet goes way back into the case causing the pressures to increase (hence the geometry change for NATO). Hand loading for bolt guns where you can load the bullet out so it doesn't go into the powder space is a much better solution though approach with care per any hand loading venture. For semis where mag limits are a concern requires proportionally more care in load development.

On 7.62/.308 it is NOT the neck and leade that is an issue. (In .223 we are going from light 55gr to heavy 62+gr bullets in the debate in .308 the MilSpec bullet is quite light at 147gr nominal.) The problem can be at the base in the case (this can also be an issue if you load 5.56 velocity and bullets in commercial brass). If I get all crazy some night I will take pictures of some bullets in case mouths and sectioned bases in .308 to show this for sure (but I digress).

The MILITARY case is required to be much thicker through the base than the commercial equivalent. Ever wonder why those loading manuals say back off 2 grains? Well now you know, there is that much extra brass in a military case compared to a civilian case. (Correctly pointed out as due to the full auto guns tendency to really rip on the case to get it out of the chamber and in the case of the G3, while it is still pretty highly pressurized. There are also cost implications if you can save that brass on several million cases you make more profit! And other things but we again digress.)

So what right? Well you get into last point of support on the base of the CASE issues with civi ammo in military guns. Not all of them BUT the FAL design is famous for leaving a lot of case out of the back of the chamber when it is in battery. Look at your Military brass after firing in your FAL versus say your Remington 700 (factory!) and see where the brass swells to: quite a bit further forward in the military piece. Commercial brass - Remington is the worse I have seen regularly for thinning the case base but others are close - can often let go at the base in these less than fully supported Mil Spec barrel/chamber designs. In normal Mauser, Remington, Winchester type bolt rifles with factory barrels you should never even notice a hitch with either kind of ammo.

Lastly in the .308/7.62 debate be REALLY CAREFUL when you buy a rebarreled gun or rebarrel a gun. I had several pictures and ruptured cases sent to me in the 80s that had a chamfer on the back of the chamber made to ease loading for single shot target rifles. With military brass it held together. With some foreign and civi brass it had a habit of occasionally blowing out a case base and sending gas into the breech. If in doubt and you are loading a new non-NATO Spec ammo into your FAL, M14, HK91, etc. pull a bullet and section the base. Do a few from Remington, IVI, Winchester (commercial) and Lake City and check it out for yourself. With commercial guns caveat emptor and do some checking or ask your gunsmith to look into it.

Safe shooting. Of anyone has specific gun combo question message me privately please.

Phil
 
A. call the manufacturer (most of the serious companies build them to handle both - Colt in AR15A2s and more recent, Steyr AUG (only Scout and SBS are .223))
Click to expand...

So, is there a consolidated list on here for which manufacturer's make their rifle which will safely chamber both caliber's? I'm specifically wondering if the Norinco CQ can receive the 5.56mm (please leave opinion out on this rifle... I have kids to feed :D)
 
yeasr ago I was doing some work with Savage. This was when I was suggesting a 1:9 223 and a single shot target rifle configuaration.

The prototype rifles came to Canada (20 of them) with conventional 223 chambers. These were no good for the Sierra 80 and not so good for 5.56. I had to touch each chamber with a Wylde profile throating reamer.

I suggested Savage use a Wylde match chamber reamer, but instead they usedd a SAAMI chamber with a NATO throat. This seems to have worked well. This rifle is safe with 5.56 ammo. Most Remingtons I have looked at ahd deep throats. Have not checked a Remington 223, but assume it has the deep throat, too.
 
You must log in or register to reply here.
Back
Top Bottom