I've been trying to figure this one out. I bought this upper from a friend....who bought it from a friend...etc.

She shoots great, no failures of any kind. I get about 3/4" groups using 5.56 M193 and about 1" groups using PMC .223 depending on the day and how many beers I've had. Haven't tried any other ammo through it yet.

My question....Did Colt make this upper with the reciever stamped Colt 223 and the barrel stamped 5.56 NATO for a reason?

Is this why the term Wylde came about?

Has it been re-barreled maybe?

Or something else?















Any constructive insight will be appreciated.

Thanks,
Mort

that bbl is colt (C MP); wylde chambering is by RRA

try this: www.ammo-oracle.com

and this: www.biggerhammer.net/ar15/barrelsbolts/

ETA: oh yea, your bbl is "5.56"--pay attention to the markings on the bbl, not the reciever/lower

Quoted: that bbl is colt (C MP); wylde chambering is by RRA try this: www.ammo-oracle.com and this: www.biggerhammer.net/ar15/barrelsbolts/ ETA: oh yea, your bbl is "5.56"--pay attention to the markings on the bbl, not the reciever/lower

Hey...Thanks for the info on that Ghost....Really!!

But I'm more looking into the build of this upper. And why it is stamped Colt 223 on the upper reciever. And then stamped 5.56 on the barrel.

Just trying to figure it out?

Thanks,
Mort

Quoted: Quoted: that bbl is colt (C MP); wylde chambering is by RRA try this: www.ammo-oracle.com and this: www.biggerhammer.net/ar15/barrelsbolts/ ETA: oh yea, your bbl is "5.56"--pay attention to the markings on the bbl, not the reciever/lower Hey...Thanks for the info on that Ghost....Really!! But I'm more looking into the build of this upper. And why it is stamped Colt 223 on the upper reciever.

because it was sold as a replacement upper, not a complete rifle. Colt used to mark their replacement uppers that way. I had one in 7.62x39mm with ther upper marked in the caliber, as well as the brl.

Colt used to mark their replacement uppers that way. I had one in 7.62x39mm with ther upper marked in the caliber, as well as the brl.


Yea I completely understand! You live in an entirelly different world then the rest of us.

Good Luck to You!

Now can we please get serious?   Awe fuck it!! I just realized I'm talking to the Night Shift!!

Thanks anyway,
Mort

556 NATO is your chamber.  The complete upper is a replacement as stated earlier. It most likely is the original barrel for the upper.  

Quoted: Quoted: wylde chambering is by RRA Give credit where credit is due. Bill Wylde designed the reamer that has come to be known as the 223 Wylde. This design has been around longer than Rock River Arms has been making or selling anything. From a Zediker article: So the rest of this will make sense, the following dimensions are all based on an overall cartridge length that will have a Sierra 80-grain MatchKing bullet just touching the lands when the round is chambered. We don't all shoot Sierra 80-grain MatchKings, and we don't all set them to touch the lands, but most competitive High Power Rifle shooters do both. At the least it's a "standard" that gives us a point to work from. What I call the "Derrick Chamber" (Derrick Martin of Accuracy Speaks) needs an overall cartridge length of 2.442"; the "Wylde Chamber" (for competition-use AR-15 pioneer Bill Wylde) is 2.445"; the "AMU Chamber" (for U.S. Army competition team) is 2.500". There are others, but these are the most popular among competition rifle builders. A SAAMI chamber is normally about 2.410"; a NATO chamber is normally about 2.550". Those are huge differences, and I counted five different reamers just mentioned here. Link: findarticles.com/p/articles/mi_m0BQY/is_9_51/ai_n14816186

ah yea, sorry about that mr randall...ok i'll rephrase in more words in which i ment in the origional post: "most wylde chambers in today's commercial AR market are usually RRA" (that sounds pretty correct, right?)

i know there are several folks who go w/ .223 wylde and that RRA didnt develop it (but i didnt know WHO, thanks for that tidbit), but i'd always thought that RRA was the AR company that made the .223 wylde catch on/popularized in the past several yrs...

A large number of aftermarket barrel manufacturers use the Wylde chamber.  If you look at all the stainless high end barrels in the EE probably half have the Wylde chamber.

Quoted: A large number of aftermarket barrel manufacturers use the Wylde chamber.  If you look at all the stainless high end barrels in the EE probably half have the Wylde chamber.

definitly...h/w, i'm refering to those bbls attached onto the ABCDRS, oly, etc commercial brands of complete ARs (which make up a majority of the AR market vs. the more customized bbl manfs) and to which of the top 8 or so, RRA is the most predominate that uses wylde chambering (rest tend to be 5.56 or .223 as you know)