Trying to learn about AR

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jcramin

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Im looking at some ARs and just trying to learn some things. I see on the DPMS web site

If DPMS barrel is stamped as 5.56 you may use either type of ammunition, if it is stamped .223 you should only use .223 ammunition.

OK SO when I go to Bass Pro or someplace and buy AMMO I only seem to see .223. Am I not looking right or do most retailers only sell .223. Where would you buy 5.56 if I got a gun that was a 5.56 ?

ALSO is their an advantage of buying .223 or 5.56 over the other ??

I understand they are the same size bullet ??? is that right ? But 5.56 is made if thicker brass ???

ALSO is 5.56 and 5.56 NATO the same thing ?

I just want to learn before I jump in too far LOL

J
 
I'm new to AR's as well so don't be surprised if someone comes along and contradicts me but:



OK SO when I go to Bass Pro or someplace and buy AMMO I only seem to see .223. Am I not looking right or do most retailers only sell .223. Where would you buy 5.56 if I got a gun that was a 5.56 ? I think to get 5.56 you'd have to buy online through military surplus dealers.

ALSO is their an advantage of buying .223 or 5.56 over the other ?? The advantage is that with a 5.56 you have the option of both

I understand they are the same size bullet ??? is that right ? But 5.56 is made if thicker brass ??? This i'm not sure of...sounds right though

ALSO is 5.56 and 5.56 NATO the same thing ? yes

I just want to learn before I jump in too far LOL
 
5.56mm is loaded to a higher pressure than .223, aside from the thicker brass. Also, since 5.56mm is a military cartridge, it usually contains flash retardants in the powder as well as some type of seal around the neck and the primer pocket to keep out water.

Some retailers sell 5.56mm and some don't. I can go to my local Sportsman's Wharehouse and buy Winchester Q3131, or Shooter's Den (a local store) for Federal XM193.

I prefer to shoot 5.56mm out of my Bushmaster instead of .223 Rem.
 
jcramin,

here's a good start as far as 223 vs. 5.56(higher pressure/slightly diff case). FYI, I was shooting 5.56 reloads on a hot summer day in a 223 Savage Tactical bolt action and blew a primer/case head which also blew the extractor on the bolt face. In simple terms you can shoot 223 in a 5.56 but never the reverse(to be on the safe side).

http://ammo.ar15.com/ammo/project/hist_diff.html

also check out,

www.ar15.com forums for lots of great info.

Enjoy. I got my first ar last sprin, a Rock River Entry Tactical. I've only put about 150 rounds through it but the first time I squeezed the trigger it's was all smiles from ear to ear. You'll like it.
 
You can try reading through my blog (linked in my signature), hopefully you can learn a thing or two. I try and add to it often. There is a bunch of info in there, but there is plenty of more info to be added...
 
5.56 is also loaded to higher pressures and usually gives you more velocity.
 
Well, in short yeah you can. Are there issues with it, well maybe so..... Will it blow your gun aparts and send pieces of the gun thru your brain housine group, probably not. But lets take a look at what the issues are for reals.

First of all there are three major types of AR chambers. The .223 SAMMI, the .223 Wylde and the 5.56 NATO. It's all so crazy and convolutted that we will skip right to the point of it all and look at it in laymans terms.

The real issues are the case neck, freebore length, throat angle and headspace. Now what do they each mean?

Case neck- Thats where the bullet sits in the case.

Freebore length- Thats the length between cases end and where the lands and groove start. This is where the bullet is actually free in the bore when it leaves the case. This affects the pressure of the round as the lands and grooves cause pressure to build behind the bullet.

Throat angle- This is the angle of slope where the freebore ends and transitions into the lands and grooves.

Headspace- This is the depth of the chamber

Now the headspace on all chambers is the same at 1.4636, so that is a non issue. The throat angle is significantly different though, 3 degrees for the SAMMI and 1.25 degrees for the other two. How does this affect you? It makes the pressure in the SAMMI start quicker as pressure is appled more abruptly.

Freebore length is a big issue in the three. The freebore for the SAMMI is a mear .025, the Wylde is .062 and the 5.56 NATO is .057. What does that mean? It means that the SAMMI builds pressure a lot faster than the Wylde or NATO chambers. Add this to the fact that NATO rounds are already a few hundred feet per second faster and as much as 5,000 PSI higher in oressure and you have an issue building rapidly. As is the pressure.

Does this mean that your gun is going to explode by using NATO ammo in your .223, probably not. They are massively over engineered and generally pretty safe for these kinds of things. They are designed to take pressure spikes, however I DO NOT RECOMMEND IT. It simply is not safe. You WILL probably start to see primers popped out of the cases or swollen.

So what do we do about it all? Well, we try to order all of our AR's in the 5.56 chambers. That allows you to shoot whatever you want to in the gun. The next thing you can do is shoot .223 ammo in your guns. Milsurp is not as cheap as it used to be, so there is not much advantage to go that route anymore. But if you do find a deal having a 5.56 chamber is going to make life more comfortable for you. But if you dont have a 5.56 chamber, just dont shoot milsurp ammo.
 
WOW thanks, that helps A LOT now I understand. I am sure I will have more questions soon.

Thanks,
J
 
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