Looking for suggestions to replace my Colt ar 6721 stock hand guard.  Looking for a drop in rail (no modifications required) that is lighter and smaller diameter than stock.

Found two candidates, looking for more suggestions or your opinion on the rails. Links are embedded...

1) Yankee Hill AR-15/M16 2 Piece Handguard

2) Daniel Defense Omega 7 Rail

I have the DD Omega, on my 6920, same animal different barrel.  I like it.

DD.

It's also free float

I have a Knight's Armament Co. (KAC) M4 RAS rails on my 6721 carbine, it's very well proven by the US military on their M4 carbines.

These KAC rails are slightly wider and heavier than the factory standard issue M4 handguards.

Look around at the Equipment Exchange usually they're $150 or under or check KAC's web store they have blems with unnoticeable finish flaws.

Out of the two you mentioned I would get the DD because it is a better free floating design and no mods required to mount it.

I have a DD EZ 7.0 CAR drop-in rails (non free floating) on my other carbine and it have excellent quality but they no longer make it.

I went out on a limb and bought the utg super slim drop in carbine handguard. It is their pro products. All I can say is wow. Light and ultra slim. Check it out.