The RISII Hardware Pack includes the replacement mounting parts required to install a Black MK18 RISII or M4A1 RISII Handguard. This hardware is included with the purchase of a complete rail system and will only be necessary if you damaged or misplaced your original parts.
Included in RISII Hardware Pack:
- 1x Bolt Up System Barrel Nut
- 1x RISII Bolt Up Plate- Black
- 4x Long Socket Head Rail Screws
- 2x Short Socket Head Rail Screws
- 6x Flat head Rail Screws with Washers
Not Included but needed to install:
- Bolt Up System Barrel Nut Wrench
- 5/32” Allen Wrench
- Flat Head Screw Driver
|Product Weight||3 oz|
- Cost and weightqualifications are BSME and BSEE. I worked my way thru college working as a tool and die maker. I still love to shoot and have built a very good 556 SBR with a DD 11.5" BBL and a 300 AAC SBR 9" BBL. One thing I wanted was a free float system that I could swap components from one rifle to the other. I found that there was failure of the barrel nut due to sub straight load capacity combined with the available surface area. I also added an Adams arms gas piston system to the 556. The barrel nut was custom machined to allow for the required indexing of the nut in relation of the push rod thru the upper receiver. The nut was bored out inside and I added a 4140 hardened washer with increased surface area to support the load required. Without this, the nut would fail causing the quad rail to tilt in an undesirable and unstable position. It has worked flawlessly since I made these modifications. I understand the need to use steel for strength but reinforcing the nut will save weight by 65% and be stronger than ever needed in combat with proper design. This will also help in cost. I suggest lightening the rail somewhat by reducing it's mass. Every ounce of mass that can be saved makes for a faster operator in movement during firing and maneuvers. Feel free to comment back to me if you wish to further discuss this or other matters. I installed your rail system for a friend and found it to be a very good product, but for civilian use the cost very prohibitive.