Armalite's standard bbl's are chrome lined as well. However bushmaster offers light weight bbl's and more bbl configurations.

I like to shoot my M15A2 hbar, but I wouldn't want to have to carry it a lot.

[i][b]"If you're not part of the Solution,
you're part of the problem"[/i][/b]

sgb

Ches here is what you are getting:

Colt: the Name, M16 chrome lined chamber and unlined bore.  Tourgher to clean, marginally more accurate.  Usually they have the best QC but they have been slipping of late.  Fire control pins are non-standard (tougher/more costly to get replacements and trigger upgrades) and the buttplate is now a cheap plastic. Company's executives are NOT pro gun.  Poor customer service.

Armalite:  Great fit and finish.  Chrome lined barrels & bores, but chamber may not be to M16 specs (Armalite keeps claiming they are going to switch over, but when asked they say they have not done it yet).  Lifetime warrenty, good customer service.  Barrel uses the cheaper 4140 steel (BM & Colt use mil-spec 4150).

Bushmaster:  Cheaper price, chrome lined bore and chamber with 4150 steel.  More options from the factory. Great customer service.  Best bang for the buck IMHO

Armalites a looker and has that lifetime warrenty.  Bushmasters have the edge in reliability (over Armalite, not Colt) and lower cost .  Colts have 'The Name'.

All three are generally fine rifles and all will serve you well.