[Herman]

I own A Colt Match Target Competion HBAR. I am a First Generition gun owner. I bought A Pre Ban Colt. I could not get it to Fire More Then a few rounds.It was new in the box Even. I tried over 20 plus clips an every kind of ammo on the market. I sent it back to Colt and the said they fixed the problem. It ended up even worse off. So I bought The A3 Competion model and got rid of the pre ban. I just have a very few questins Why does my Colt Barrel say MP 5.56 NATO 1/9 Twist.The reciever says 223 It weighs 8.5 pounds With no clip. The gun I have know is built like a tank and shoot Awesome. So my Questions Are What does the 1/9 twist mean could anybody help me with that? The last one is should I Buy 223 rounds or 5.56 From my under standing the 5.56 is a hotter round any truth to that? Thanks,( [email protected]@gmail.com)

Herman

 

[Dillinger]

1 in 9 twist is the rate of 360 degree rotations a bullet will make in 9 inches of barrel. In this case, it will make one complete revolution for every 9 inches of barrel. 18 inch barrel? 2 revolutions.

"Currently Colt marks most of its barrels C MP 5.56MM NATO, followed by the twist rate. The “C” means the barrel passed all Colt quality control checks and the MP certifies that the barrel passed high-pressure testing and magnetic particle inspection. Many of the shorter Colt 223/5.56mm barrels have abbreviated markings. Since 1964 all Colt select-fire lower receivers are marked with the metric “5.56MM” designation and most semi-automatic only lower receivers are marked with the American “CAL. .223,” which reinforces the fact that Colt recognizes no difference between these two “caliber” designations."

^ Info and plenty more to rattle your brain can be found here

D

 

[kirby62]

D's got it completely right. I just want you to hear from some one else. The two kinds of ammo in question are the same.

 

[Righteous]

223 is civilian round and 5.56 is Nato/military round, you get alot higher pressure loaded with the 5.56 ,

 

[bkt]

The 5.56 NATO round and a Remington .223 are very similar, but they are not the same. A receiver chambered for .223 should not be used with 5.56 ammo, but a receiver chambered for 5.56 should work fine with .223 ammo.

From A Reliable Source on the Internet [TM] (if there is such a thing):

The primary difference between .223 Remington and 5.56x45mm is that .223 is loaded to lower pressures and velocities compared to 5.56 mm. .223 Remington ammunition can be safely fired in a 5.56 mm chambered gun, but the reverse can be an unsafe combination. The additional pressure created by 5.56 mm ammo will frequently cause over-pressure problems such as difficult extraction, flowing brass, or popped primers, but in extreme cases, could damage or destroy the rifle. Chambers cut to .223 Remington specifications have a shorter leade (throat) area as well as slightly shorter headspace dimensions compared to 5.56 mm "military" chamber specs, which contributes to the pressure issues.

So, stay away from hotter loads if you're chambered for .223.

 

[RMTactical]

You really need to read this all the way through, maybe twice.

http://ammo.ar15.com/

 

[rnds on time & on target]

EXCELLENT ANSWER, dillenger! brief, yet factual and accurate, and you did'nt give any of the bs often given over 'newb questions' from beginners either, my respect for you and your work is rising quickly, and i only found this site tonight...

In the australian army we use the metric system, and 5.56x45mm (the SS-109 rnd) is virtually identical, to ".223 "with some minor variances i think, in terms of loadings & pressures, but it's still much the same as the rem .223 cal , which is just the imperial measurement of the projectile's caliber, just as what you call the .308 cal ,we call the 7.62x51mm and so forth (yet strangely you still call a 9x19mm a "9mm" is .356 in yours ,etc.)

and our f-88 AUS STYER AUG's have a 1/7 rifling twist, which is about perfect for the SS-109, my own experience with using surplus mil-std 109rnds in my friends ruger mini-14 and my AR-15 some years back, did seem to have some oomph, but fired & cycled without so much as a hiccup, and we fired alot of it back then 'cause it was much cheaper than imported remmington stuff, so i know of no reason the 2 are not fully interchangeable, as long as as you dont mind more/higher pressures in your rifle.

hope this is helpful, cheers.

Well, BKT above has said it even better, e'nuff said!

 

[Dillinger]

EXCELLENT ANSWER, dillenger! brief, yet factual and accurate, and you did'nt give any of the bs often given over 'newb questions' from beginners either, my respect for you and your work is rising quickly, and i only found this site tonight...

Thanks brother, but I am no expert. I work, part time, as a gun shop apprentice - but it drives me crazy to read some posts on line, especially about the AR field, that are so completely just flat assed wrong.

I have banned together with a couple of great guys here at the forum to help dispel some of the myths that are out there and together we are fighting the good fight.

 

[rnds on time & on target]

glad to hear it, it feels to me like your achieving your goal, i wish i'd found this site years ago, in the short couple of hours i've been posting here i hope i have'nt offended anyone enough that you cant use one more in that fight..my ownership of my AR is now iffy at best, (i understand that this site does'nt condone that, already, but now that i can't take it to a gunsmith anymore, or get it seen-too in any way, i rely on very accurate info to help me troubleshoot anything that my military background or my very limited metalwork skills cant cover..but as you already know, most sites seem to know less than i do, and i'm no expert either, mate..so i can empathise with your fight! if any of your questions are anything i can help with, I'll give you all the help i can, but i'm not on-line @ home, so it may only be on & off checks through-out the week, if thats any help too you guys/girls.

(dont worry, all my other guns are perfectly legit, so far!)

YOU CAN MAKE A THRONE OF BAYONETS..BUT YOU CANT SIT ON IT FOR LONG! -yeltsin

 

[matt g]

glad to hear it, it feels to me like your achieving your goal, i wish i'd found this site years ago, in the short couple of hours i've been posting here i hope i have'nt offended anyone enough that you cant use one more in that fight..my ownership of my AR is now iffy at best, (i understand that this site does'nt condone that, already, but now that i can't take it to a gunsmith anymore, or get it seen-too in any way, i rely on very accurate info to help me troubleshoot anything that my military background or my very limited metalwork skills cant cover..but as you already know, most sites seem to know less than i do, and i'm no expert either, mate..so i can empathise with your fight! if any of your questions are anything i can help with, I'll give you all the help i can, but i'm not on-line @ home, so it may only be on & off checks through-out the week, if thats any help too you guys/girls.

(dont worry, all my other guns are perfectly legit, so far!)

YOU CAN MAKE A THRONE OF BAYONETS..BUT YOU CANT SIT ON IT FOR LONG! -yeltsin

You've offended no one. Just owrk on keep things on topic and well formatted.

 

[dragunovsks]

They are the same round, my AR is stamped .223 cal (5.56mm) on the reciever. 5.56mm is a metric measurement, converted to English/US inch measurement it's actually a .225 which is very close to .223.

http://www.warwheels.net/CaliberConversionChartHAUGH.html

 

[matt g]

They are the same round, my AR is stamped .223 cal (5.56mm) on the reciever. 5.56mm is a metric measurement, converted to English/US inch measurement it's actually a .225 which is very close to .223.

http://www.warwheels.net/CaliberConversionChartHAUGH.html

That's not true at all. Why do you think .223 Wylde was created? Even SAAMI will tell you not to fire 5.56x45 mm in a .223 Rem chambered weapon.

 

[dragunovsks]

Then why is it stamped on my rifle? I've never heard of .223 Wylde.

 

[matt g]

Then why is it stamped on my rifle? I've never heard of .223 Wylde.

.223 Wylde is a compromise between the chambers of .223 Rem and 5.56x45 NATO. It's designed to withstand the higher pressures of the 5.56x45 NATO.

 

[M14sRock]

If you have an AR and the bbl is stamped 5.56, but the receiver is stamped .223, go with the stamps on the bbl.

The rounds (.223 and 5.56x45) are not the same. The 5.56 chamber has a longer throat (the part of the chamber just before the rifling begins). And the 5.56 has higher chamber pressures.

The bbl markings dictate the chamber dimensions, thus the caliber. 5.56 will fire .223 with no problems.

The .223 chamber will tend to be more accurate, due mainly to less free travel of the bullet (as it crosses the long throat).

And it has been very common for shooters to use each round in their rifles, no matter the markings, for many years. Problems are rare, and are usually reliability related, more than safety related. But you should still heed the warnings of SAAMI and use the right caliber.

 

[dragunovsks]

I understand to go with what the barrel says but my rifle is stamped .223 cal. followed immediately by (5.56mm) on the reciever.

 

[Dillinger]

I understand to go with what the barrel says but my rifle is stamped .223 cal. followed immediately by (5.56mm) on the reciever.

Essentially what you have is a receiver that a company has put before a testing committee, and probably a lawyer or 3, and determined that their rifle will safely fire both the .223 Civilian and the 5.56 Nato without anything happening to you, the end user.

If you had an AR, for example, that was rated for .223 caliber - and said nowhere about 5.56mm, but you used it and something happened, because the 5.56mm runs at a hotter pressure, that company could be liable.

That is where .223 Wylde came in - it's a compromise chamber that will safely accept the different throat lengths of the two cartridges, as well as the higher pressure of the 5.56.

JD