The Riflespeed adjustable gas block, .875 journal, 4.3-inch assembly, lets you tune the gas on an AR-15 or AR-10 without tools. A numbered control knob with a tactile click for every setting makes each adjustment repeatable, so you can return to a known setting for suppressed fire, different ammunition or changing conditions. Riflespeed identifies this length as model RS8743, and the last two digits give the assembly length. It requires a straight gas tube, which is not included.

Key Specifications

• The journal diameter is .875 inch, so it fits barrels with a gas block journal of that size.
• The assembly length is 4.3 inches, which is the dimension to check against your handguard and muzzle device.
• Adjustment is tool-free through a numbered control knob with tactile clicks, so settings are easy to read and repeat.
• A rotation stop keeps the knob from turning far enough to unintentionally disassemble the control.
• It requires a straight gas tube, either Riflespeed or an equivalent, and the tube is not included.

Frequently Asked Questions

Which cartridges does it work with? Riflespeed lists .223 Remington and 5.56x45mm, 300 AAC Blackout, .308 Winchester and 7.62 NATO, 6.8 SPC and 6.5 Grendel, plus other cartridges with the correct plunger.

Does it need a special gas tube? Yes. It requires a straight gas tube from Riflespeed or an equivalent, and the tube is not included.

Buy the Riflespeed Adjustable Gas Block, .875-Inch Journal, 4.3-Inch Assembly

Riflespeed built its gas controls to be set once and repeated, so changing ammunition or adding a suppressor no longer means guessing at the gas. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and see more AR-15 accessories and parts while you are here.