Colt/SA Gas Block

A Pinned SA Operator Gas Block from a Standard Colt Front Sight Base
Here’s how it all starts, with a factory Colt barrel assy. When we first began engineering and fabricating these custom Operator Series gas blocks in 2004, our goal was to fit the actual Colt factory gas system inside the narrow confines of the new Gen1 LaRue Tactical 9.0 rail. Today we fit our Colt/SA gas blocks inside several different rail systems.
This is the Colt front sight Base (FSB) mounted to one of eight different machining fixtures that we use to create the SA gas block. This operation will remove the bayo lug and sling swivel attachment. Remember, the FSB must stay with its barrel assy at all times. These parts are NOT interchangeable!
After visiting several machines and work stations, the FSB is no longer recognizable as the Colt part that it used to be. But it is still an absolutely critical piece of the AR-15 gas system. The GIANT custom pins are used to allow plenty of material for a tight press-fit.
Now the pins have been machined off and contoured using a rotary fixture that we designed in-house. With some final surface grinding and buffing, the SA pinned gas block is coming to life. It is a long way from the FSB in the first photo.
Once all machining operations on the gas block are completed, we move on to final surface prep and phosphate plating. This includes the barrel assy and anything attached to it. These last steps are critical and must be done with great attention-to-detail.
As you can see in a couple photos above, this barrel assy has a Daniel Defense (DD) RIS II barrel nut. Now it is time for all the components to come together in final assembly. Our precision SA barrel wrench will bring military-grade torque to this barrel nut for proper installation. Note: The RIS II barrel nut is a good design, but it requires tooling far beyond the toy-wrench that comes in the box.
Here is our pinned gas block visible from the front. It now hides inside a new AR-15 LITE RAIL III 9.0 from Daniel Defense, which was supplied by the owner, but it is still the exact same gas system which left the factory years ago. No aftermarket issues, no leaks, no set-screws, no problems of any kind. Just ready to go.
Side view of the DD rail system. Very nice quality product. This particular Colt carbine has the standard SA Reliability Package mods and lives in Ohio. Runs like a lightweight punch press.