+1
What they said, either get a HBAR model with chromed barrel and a mag fenced lower, reprofile the barrel or change the barrel with a Gov't profile.
I was also looking for an A2 Colt model last year and I can't find one so I just built one myself.
I bought a new surplus Colt M16A2 upper half and I also bought a new post ban Match Target HBAR model MT6601 stripped lower receiver and I just installed a Colt LPK and a M16A2 buttstock assy on it.
The only feature that the MT6601 lower doesn't have is the hole for the pivot pin detent, however other models such as the MT6700 Match Target Competition HBAR or the MT6400C Match Target M4 carbine (etc.) some have it, check this feature before you buy it.
On my MT6601 lower I'll just have the hole for the pivot pin detent added by my gunsmith, no big problem.
Good luck.