Mad Bull Barrel Nut Washers 4pc

Convenient set of 4 barrel shims for M4 style rifles
These washers will ensure a contour fit between barrel nut and upper receiver, eliminating misalignment and RIS instability.

Included: - 0.1mm X1
- 0.15mm X1
- 1.5mm X1
- 2mm X1

Features:
- Eliminate gap between rail and upper receiver
- Precisely aligns fastening screws on RIS systems
- Ensures stability
- Prevents RIS from angling during installation