The 11.5” complete upper in 5.56mm features an OD Green upper receiver mated to a unique Mk16 MLOK rail with 11.5”  Black Oxide coated, Cold Hammer Forged Geissele, Chrome Lined 1-7 twist barrel, with nano-coated Surefire closed tine Surefire SOCOM flash hider and a Geissele low profile bomb-proof factory installed gas block.

This is a Geissele Factory upper.

Geissele barrels are a new line for Geissele in 2020, and further refined in 2021.  The barrels are precision machined and cold hammer forged. The carbine length gas system is perfect for the 11.5" barrel, and includes a Geissele gas Block installed at the factory with both lower set screws and a through the barrel pin.  This is something Geissele has been doing since 2018.  Is it necessary? No.  Extra protection from a gas block moving, which was never going to move in the first place, but something about the Geissele name has that German sound to it, that causes the entire firm to over-engineer, like Mercedes.

The newly designed 10.5” Super Modular Rail MK16 mates to the upper via a center aligning tab removing any chance of rail rotation. This rail is a variant of the 13.5” SMR MK16, currently fielded by USASOC, and one of Geissele's best sellers and best ideas.  At Charlie's, we like the way in which the upper mates to the rail, which also is a crutch to better align the rail and upper receiver.  That is a good thing.

As a Charlie's exclusive, you have your choice of the Geissele Reliability Enhanced Bolt Carrier Group.

The Geissele contracted mil-spec BCG has been featured in Geissele's very popular M4A1 and Mk18 URGi for the last two years. Each bolt is rigorously inspected, high pressure tested, mag particle inspected.  The mil-spec BCG is produced by a Tier-1 military defense contractor and has a standard tried and true military phosphate coating and oiled and chrome lined chamber for the bolt.  The Geissele REBCG is Nano-coated for lubricity and superior protection from the elements.  The

The Reliability Enhanced BCG is DLC coated in what Geissele calls "Nanocoating" and is machined from mil-spec 8620 steel, with a properly torqued and staked, chrome lined gas key. The REBCG also features extended upper rails, providing greater stability and dramatically increasing feeding reliability. The REBCG is properly torqued and staked, chrome lined gas key. The Cam Pin is machined from advanced, medical steel known as H13 which is also coated with Nanoweapon for maximum corrosion and wear resistance. The Geissele Reliability Enhanced Bolt Carrier Group also features extended upper rails, providing greater stability and dramatically increasing feeding reliability.

The Geissele Reliability Enhanced Bolt Carrier Group comes with the Geissele Stressproof Bolt. Made from Carpenter 158+, directly developed with Carpenter Steel metallurgists to create a material that is cleaner and has less impurities. This makes our Stressproof bolt stronger and more fatigue resistant. The Geissele Stressproof bolt is also forged, not machined from barstock. This allows us to optimize the grain structure of the steel to yield a bolt capable of 5 times the life of a mil-spec bolt. Each bolt is rigorously inspected, high pressure tested, mag particle inspected and Nanoweapon coated.

Nanoweapon coated, and requires less oil.

The Super Duty upper also includes the  Airborne Charging Handle.  The Mk16 rail is unique to this upper, as it has the dovetail fit to the upper.  This is not a standard Geissele Mk16 rail, nor is the upper a standard Geissele upper.  The two are meant to be used as one system.

Note:  Geissele has, over the years, used a number of forgings for their upper receivers, as well as a number of different flash hiders.  This particular forging in 2021 is either Brass Aluminum or Mueller forging.  No matter the forging, Geissele is testing each upper receiver for functionality and blemishes before putting a passing grade on the upper receiver.  Don't get hung up in the super details.  Trust the gun maker to make the right sourcing decisions.  We do.

The Super Duty Complete Upper from Geissele Automatics offers unmatched performance, accuracy and reliability.