Up for sale is my Colt 6920 upper with a Midwest Industries FSP rail. I bought this new and have only fired about 60 rounds through it. The barrel is the standard 1:7 twist colt gov't profile.
The Midwest Industries rail is a free float rail with built in QD sockets. Its this one with the FSP cut out:
It comes with the stock Colt charging handle and a Nickel Boron coated full auto bolt.
$600 shipped, PP Gift or +3% or USPS MO.
It can be purchased with the LNIB Aimpoint pro with cantilever mount for $1,000 total.