Griffin Armament—Adjustable AR-15 Gas Block

According to the company, it has long been Griffin Armament’s belief that the ideal AR-15 gas system should have two simple modes—Normal and Suppressed—affording a KISS (keep it simple, stupid) concept optimization for use with and without suppressors.

Ideally, it would be easily adjustable by tool-less means, or at the least using a tool any sport shooter or rifleman has ready access to. A tool such as a round of 5.56mm ammunition, which may be already used, for example, to remove the firing pin retaining pin from the bolt.

The new Griffin Adjustable AR-15 Gas Block achieves this simplicity, and it is a product made possible by the acquisition of two patents from MicroMoa LLC, the original manufacturers of the “Govnah” gas block.

True to its stated mission, the Griffin Adjustable AR-15 Gas Block provides normal and suppressed operation via rotationally sliding a 17-4 regulator plate from the Normal position to the Suppressed position. This regulator plate is detented by a 718 inconel spring and ceramic ball bearing to ensure reliability under extreme operating temperatures.

There are two 180° opposed sides of the regulator plate—each identifiable from the other, and each side affording a normal and suppressed setting to give the user a choice between two slightly different suppressed port holes in the chosen configuration.

The suppressed gas ports on conventional plates are .004″ apart offering two sizes, and the low-backpressure plates offer two sizes .008″ apart (with the exception of the .300 BLK plate).

To date, Griffin Armament has developed a total of nine plates to address the majority of setups in the hands of most end users today. Additionally, they offer two pre-drilled “Drill Your Own” plates with .033″ starting holes to improve the ease of drilling. This allows users to determine and drill the preferred hole sizes for the desired results.

One of the pre-drilled options has the two .096″ normal (unsuppressed) operation pass through holes pre-drilled, and the other has all four holes spot-chamfered to .108″ with .033″ pre-drilled starter holes only, allowing customization of all four port sizes.

Which plate you should use depends on the host firearm’s gas system length, its caliber, and the type of suppressor being used (conventional or low backpressure/high flow), or a combination of both for those with extensive suppressor collections.

In sum, rather than providing a one-size-fits-all adjustable gas block solution, the Griffin adjustable gas block is more tailored to your setup making changing settings simple without the need to remember numbers or positions. This simplistic and visually objective two-position adjustment eliminates confusion and allows users to easily identify what state the rifle is in at a glance.

Finally, this gas block was designed to fit underneath most rail systems on the market and to be accessible through the slots in the rail. It requires the use of a straight gas tube. A .625” version for pencil barrels is planned, and a future AR-10 model will accommodate a normal bent gas tube.

Purchase includes the user’s choice of regulator plate; additional regulator plates may be purchased separately. Additionally, the adjustable gas block will be offered as an optional $45 upgrade on complete Griffin Armament uppers and Griffin Armament rifle builds.

Key Points:

• 17-4 H900 heat-treated stainless steel regulator plate (user’s choice based on setup)
• 32RC hardened, black oxide finished 416R barrel-quality steel block
• .750” gas block diameter with Mil-spec tolerances for gas tube and barrel diameters
• Low profile design fits under most rails
• STD .460 knurled cup point set screw spacing
• Pre-drilled for ease of barrel pin installation
• Includes all required pins and fasteners
• Perpetual Lifetime Warranty
• Weight: 1.8 oz

Griffin Armament
Adjustable AR-15 Gas Block
MSRP: $102.95
URL: griffinarmament.com