[24601]

Looking at some M4 uppers, I was given the choice .223 or 5.56 NATO chamber. Aren't these calibers the same? I don't get it. Why choose one over the other? If so, which one?

Would it be worth $50 bucks to add a chrome lined barrel?

Finally, 16" or 14.5". Which ones are the military using?

HELP!!

 

[bren10man]

Chamber: Go with 5.56mm chamber.

Bore: Go chromed.

Military uses 14.5 inch barrel so that a bayonet can be mounted.

 

[Shoot762]

Ditto what bren10man said.

 

[24601]

Questions answered! Thanks guys!

 

[Oddball]

You probably already know this but just in case...

If you do go with the 14.5 in barell, you will need to pay to register the rifle w/ the ATF as a SBR (Short Barreled Rifle). Or you will need to have someone permanently attach a flash hider that will bring it up to 16 inches (like a smith enterprise vortex or bushmaster phantom). The standard a2 flash hider won't quite make it 16in.

 

[DenverDick]

Go for the NATO chamber and chrome lining. I'm going with a pre-ban 16" M4 bbl with a birdcage flash hider on one of my ARs. The reasons are first, I don't run around with bayonets on any of my rifles, Garands, ARs or Swiss K-31s (I never put one on an M16 during my one year tour in Vietnam, either). :roll: Second, I want the extra velocity that a 16" barrel gives. 8) Finally, my other AR is getting a pre-ban 20" A2 Government barrel with birdcage, so I can put a bayonet on that if I suddenly get the urge...oh, yeah, and a bayonet. :wink:

JMHO

DD

 

[Cap'n Dex]

so you can't put a bayonet on a 16'' carbine? dammit! if that's the case, I won't need a bayonet stud, will I? I sure am glad someone started this thread!

 

[DenverDick]

Cap'n Dex wrote:

I won't need a bayonet stud, will I

Yeah, you will. When I spoke to Bushmaster about getting new pre-ban style barrels for my post-ban ARs, I said, "How about without the bayonet lug, I don't need it." They said, that's the way the pre-bans come and they won't do it otherwise. I said, "Sure...ok...whatever as long as I get my birdcage. :wink:

DD

 

[84 C4]

Looking at some M4 uppers, I was given the choice .223 or 5.56 NATO chamber. Aren't these calibers the same? I don't get it. Why choose one over the other? If so, which one?

Would it be worth $50 bucks to add a chrome lined barrel?

Finally, 16" or 14.5". Which ones are the military using?

HELP!!

Answer to first question:
Yes...and no. .223 Remington is the civilian version of the 5.56 NATO. 5.56 NATO is a hotter round. A 5.56 chamber can fire .223 and 5.56 reliably, where as .223 chambers can only fire .223 reliably.

http://www.ammo-oracle.com/body.htm#diff

Get the 5.56.

Answer to second question:
Yes, get the chrome barrel.

Answer to third question:
Who cares what the military's using, they're using insufficient arms, anyway, get the 16" barrel.

 

[mjmensale]

The calibers are the same but the chambers are different.

.223 chambers are cut to tighter SAMMI tolerances. This allows them to use commercial and especially match ammo with better accuracy potential.

5.56mm military chambers are cut "looser" in order to function properly under severe conditions. While accuracy is acceptable, the primary concerns are feeding, firing and extraction, particularly in field conditions.

Military ammo is loaded to higher pressures than SAMMI standards, which puts additional strain on the components. The looser chamber compensates for this.

Moe

 

[DenverDick]

84 C4 has it right.

In fact, one of the AR uppers I sent to Bushmaster for a pre-ban barrel is an Eagle Arms (div. of Armailte). It was inexpensive, but has been fairly reliable. It has a 20" HBAR (heavy) non-chrome lined (harder to clean) barrel with a .223 chamber (not completely reliable with NATO ammo). I ordered a "Pre-Ban 20" A2 Government" barrel with "birdcage flash hider and crush washer." It will be chrome lined and chambered for 5.56 NATO.

Good Luck!

DD

 

[OmegaMan]

http://www.battlerifles.com/viewtopic.php?t=36907

Here's a link of a topic that I have started with the same question. It has some good things about 5.56. WIth 5.56, the chamber has more slop for irregular sized mil ammo. Also 5.56 is a hair larger than .223 and 223 chambered guns had problems with chambering 5.56 mil ammo. I never had experince with this yet, but that;s the replays I had on my post.

Also go chrome. Easer to clean after shooting ronchy ammo, also wears less. The US mil chromes theirs and I think most AK are too.

 

[RepublicanMan]

Answer to third question:
Who cares what the military's using, they're using insufficient arms, anyway, get the 16" barrel.

If it's insufficient then why would you, or anyone else want one?
I'm just curious.....I don't think many who've run into the business end of one in a CQB environment would agree with your statement though.

 

[84 C4]

Answer to third question:
Who cares what the military's using, they're using insufficient arms, anyway, get the 16" barrel.

If it's insufficient then why would you, or anyone else want one?
I'm just curious.....I don't think many who've run into the business end of one in a CQB environment would agree with your statement though.

.223 is a varmint calibre, and I don't want one. Fun to shoot though.

 

[24601]

You probably already know this but just in case...

If you do go with the 14.5 in barell, you will need to pay to register the rifle w/ the ATF as a SBR (Short Barreled Rifle). Or you will need to have someone permanently attach a flash hider that will bring it up to 16 inches (like a smith enterprise vortex or bushmaster phantom). The standard a2 flash hider won't quite make it 16in.

Oddball, NO I didn't know that. :-? Good thing I started this thread otherwise, I'd be in deep doo doo. :wink: Thanks everyone for the advice.