SIONICS Weapon Systems is an AR-15 manufacturer that should be on your radar. They are known for excellent fit and finish and for getting all the little things right which adds up to a reliable carbine. Their gas ports are right. Their staking is right. Their components are rock solid. They just get the AR-15 right and they do it for some of the most reasonable prices in the industry.
One of their newest offerings is their Geissele MKII Carbine. This has many of the same specs as their other carbines with the addition of a Geissele Automatics MKII rail and gas block. The barrel is the heart of any good carbine and SIONICS uses their proprietary medium contour, mid-length, 1 in 8″ twist, chrome lined barrels with 5.56 chambers. The Geissele MKII Carbine also features SIONICS NP3 coated bolt carrier with a HP/MPI tested bolt. It also features an ALG Defense QMS trigger and VLTOR receiver extension and IMOD stock.
The SIONICS Geissele MKII Carbine is not listed on their site yet but it available for purchase as a complete upper. The complete carbine will be available soon.
Check out SIONICS Weapon Systems.