Newbee with a possible dumb question.  I am looking to buy a Colt Match Target M4 model 6400C.  The lower says .223 Cal.  Can I still shoot 5.56 ammo with it?

Quoted: Markings on the lower receiver are irrelevant.  You could put a different upper on your lower chambered for any of at least 3 dozen calibers, and the lower would still say ".223". Your 6400C comes with a 5.56-chambered, fully-chrome-lined barrel. -Troy

I have the MT6400c, I thought only the chamber was chrome. I had the stamp codes, I can't find them now but the C stamped on the barrel meant chromed chamber, MP means magnetic particle tested. C and another letter meant chromed lined barrel. Correct me if I'm wrong because I hope I am because I would like to have a chromed lined barrel on my Colt. On a short note , I like it a lot. Theres no disappointment with it at all. I have about 5 k rounds through it using Labelle mags and genuine Colt mags and not a problem with those.

Quoted: The MT6400C, and perhaps one other current "civilian" model, are the only ones to come with a fully-chromed barrel.  The 6400 is the "M4 Carbine" and also comes with a push-pin instead of pivot screws. -Troy

Chromed line barrel, yeahhhh.......Thanks

Thanks for the info.  I'll shop around for one.