Installation requires the removal of the factory barrel nut and replacing it with Daniel Defense's proprietary hardened steel barrel nut. This requires the use of the included Daniel Defense Barrel Nut Wrench. Six Grade-8 Mil-Spec Fasteners are then used to secure the handguard tube to the upper receiver via a pair of matching aluminum Bolt-Up Plates.
- Material: 6061-T6 Aluminum
- Length: 9.55"
- Width: 2.23"
- Weight: 14.1 oz
- Inside Diameter: 1.15"
- Gas System Compatibility: Carbine w/Low Pro Gas Block, Mid Length
- Free Float: Yes
- Attachment Method: Bolt Up System
- NOTE: The MK18 RIS II is NOT Compatible with the M203
Ensure the firearm is unloaded and pointed in a safe direction. Remove the upper receiver from the lower. If there is a flash suppressor and/or front sight base, these need to be removed next. Remove the old handguard. Using a standard barrel nut wrench, remove the existing barrel nut. Place the RIS II barrel nut collar plate over the threaded receiver portion from which the factory barrel nut was removed. Thread on the new Daniel Defense RIS II barrel nut. Tighten the barrel nut down securely, making sure that the gas tube is aligned and inserted into the upper receiver. Next slide on and properly align the handguard with the upper receiver rail, and then bolt it to the barrel nut collar plate with the six included Allen head fastener screws.