- New Barrel Nut Shim For Free Float Handguard/Quad Rail .
- Works With .223/5.56/300 AAC Blackout
- Helps Improve Torque, Timing, Indexing, Alignment Of Barrel Nut
- Does Not Work With .308 Cal
- This 0.32mm Stainless Steel Shim Fits Between The Barrel Nut And Upper Receiver
Len –