The Riflespeed .750 adjustable gas block 5.9-inch assembly from Riflespeed (model RS7559) sets gas flow on an AR-15 or AR-10 by hand, with no tools, and fits barrels with a .750-inch gas block journal. A numbered control knob clicks into each setting, so you can turn the gas up or down and return to a known setting later for light commercial ammunition, higher-pressure milspec loads, suppressed shooting or hot and cold weather. This is one of Riflespeed’s Limited Exposure models, with grasping grooves that wrap around the front of the control knob so it stays easy to adjust even when the knob sits mostly underneath the handguard. The modular plunger design covers .223 Remington and 5.56x45mm, 300 AAC Blackout, .308 Winchester and 7.62 NATO, 6.8 SPC, 6.5 Grendel and other cartridges. It needs a straight gas tube, Riflespeed’s or another maker’s, and the tube is sold separately.

Key Specifications

• The gas block journal diameter is .750 inch, so it fits barrels with a journal of that size.
• The assembly length is 5.9 inches, the dimension to check against your handguard and muzzle device.
• The control knob has grasping grooves wrapped around the front, which make it easier to turn when it sits mostly under the handguard.
• Adjustment is tool-free through a numbered control knob that clicks at each setting, so a setting is easy to read and repeat.
• It requires a straight gas tube, which is sold separately, so plan the tube length for your gas system.

Frequently Asked Questions

Is the gas tube included? No. Gas controls require Riflespeed or other straight gas tubes, and they are sold separately.

What does the 5.9-inch length mean? It is the length of the assembly. Riflespeed makes several lengths so the control can sit under extended handguards, and because barrel and handguard lengths vary by maker, a shim behind the muzzle device may be needed on some barrels to add clearance.

Buy the Riflespeed Adjustable Gas Block, .750-Inch Journal, 5.9-Inch Assembly

Tuning gas is one of the most direct ways to calm a rifle that runs hard, and a click-set control makes the adjustment repeatable. Our Lubbock, Texas gun shop ships it fast and insured, and you can browse more AR-15 accessories and parts alongside it.