After thousands and thousands of rounds, looks like my pre-ban Colt M4's (Kalifornia registered AW) barrel is just about had it, or soon to be, and I am looking into purchasing a replacement barrel.

I have the following requirements:
14.5 " barrel length, with a permanent attached Phantom or Vortex flash suppressor.
Must have chrome line bore and barrel
Must have the M4 profile, no heavy barrel
Chamber must be for 5.56 NATO, not 223 Rem.
Must be able to shoot both 55 to 69 grain.
Primary defensive load, Federal Gold Match, 69 Grain HPBT.
Primary practice (school) load, Federal (AE), Winchester (USA), or PMC factory 55 grain. No reload or surplus.
I have the following choices:
Buy a BFI's M4 barrel with the Phantom FS attached 1 in 9".
Buy a Colt M4 barrel and try to find a local AW armour to permanent attached a Phantom FS, which is 1 in 7".
I am aware that Colt have special chamber dimension (slightly oval), to assist in the extraction process. On the other hand, I like the 1 in 9" barrel, since I do (can) not shoot tracer here anyway, and I had issues with my existing 1 in 7" shooting frangible (engage steel reaction target safely at pistol ranges).
I am looking for some suggestions that can give me the most reliability setup, not the most economical, because my twin M4's are my primary defensive weapon.
Any suggestions and recommendations are appreciated.

Leungken

Simple IMHO, IF IT'S A COLT BUY COLT.

I agree.  I myself prefer the Bushmaster product, but you need to keep that weapon pure.  
Colt 1/9 M4 barrels can be had, but you'll pay for it.  Twice.

True bushmaster is good but, I wouldnt put anything but colt parts back on it.
              FREE

On one of my prebans I have a cut down 16" Colt 1/9 M4 barrel with perm. Vortex. I shot about 300 rounds and is dead accurate. I would advise you to do this if you do not want to stick with 1/7 twist. yes it will cost more with all the custom work and repark, but is worth it.

I guess I am less Colt addicted, but on my Colt Carbine I am goung to use one of the Bushmaster 1:7 twist M4 surplus barrels...

See:  [url]http://www.ar15.com/forums/topic.html?b=7&f=22&t=146646[/url]

This is a NATO chamber and the color matches my Colt Match HBAR just fine.  This barrel costs half of what the Colt will cost for what is essentially the same thing!  

It's your money but you can see which way I went when I spent mine!

you're better off going with a colt barrel if you have a colt m4 upper.  colt made m4 uppers have relief cuts for the extended feed ramps on the barrel extension... bushmaster barrels don't.  if you mix a bushmaster factory barrel with a colt m4 upper, you'd better get ready for a ton of misfeeds and jamming.  i found this out the hard way... i tried mixing the two brands.  definitely a bad idea.  but if you have an older colt upper receiver without extended feed ramps or are willing to change the barrel extension on a bushmaster barrel to a colt type, then no problem.

DPMS also makes a barrel extension with the "M4" feed cuts, and it could be attached to any brand M4 barrel. If it really mattered.

You can get a BM bbl. & have the feed ramps machined in. KKF does it, & my own local funshop also does it. Yours might also. Ask around.

I have heard the oval chamber story before too and I think its BS personally.  Pure marketing hype by a gunstore commando gone out of control would be my best guess.

Thanks for all the interesting information, as stated, reliability is my primary concern, not preserving the value of my Colt.  The weapon will be my primary defensive weapon.

I got an offer from SAW in AZ, who will supply me a legalized (to 16") M4 barrel with Phantom FS (I supply) permanently attached, and their reliability package, which I think I am going to go with.

Again, thanks for all the input, and Happy New Year to you all, mean while, check six, and keep your powder dry.

Leungken