just a guess... a 223 marked lower make a rifle easier to export & import is some EU countries
Printable View
Where I put the link to the .223 vs 5.56 sticky, which is at the top of Technical discussion. No one here minds answering a newbe question, even if it has been asked and answered many times. But when one of us provides an answer and it is ignored by the questioner, it gets annoying.
I asked two different questions. Evidently You are not understandig the second one as Frens, Safetyhit and BRT870 do.With no doubt when You will understand the question You will be the first to find the right answer.
At present don't worry about the repeated question. repetita iuvant
Obviously I don't understand. Twice, you have made posts asking this question
Both times, I have given you a link to a "stickie" in the "AR Technical Discussion," titled 5.56mm NATO versus 223 Remington Chamber Differences. It is a very detailed post, including graphics, describing the very differences you are asking about. I have never addressed your other questions about Colt rollmarks.
Just to reiterate as I think I posted in this thread 2 years ago...
The Colt MT6400C that I own, and the one that my brother in law owns, both have 5.56 chambers. It is stamped on the barrel C MP 5.56 1/7 or something like that. The barrel is identical to that of the LE6920 except of course that it has a target crown instead of a threaded muzzle. The MT6400 has no comp. The MT6400C has a pinned comp.
If you go by the "chart" the MT6400C is the equivalent of a LE6920 in quality and most on this site would urge you to buy it over a Bushmaster of any model. The only downside to a MT6400C is that it is neutered, but if you are a ban stater like me that is a plus.
I live in a ban state and I own one. The only thing I don't like about it is the fixed stock. I will probably put a Sully on it when I get around to it.
Zanshin