10% micro grain premium quality carbide end mills. Uncoated, Controlled Cylindrical Land, sharp corner, and center cutting. 3/8" length of cut, 4" overall length, with 5/16" diameter shank. Our tool's correct Radial Rake insures end teeth strength. Engineered  for Aluminum high speed milling applications

For Gun Make: 80% Lower Type: 80% Tooling Country/Region of Manufacture: United States MPN: 80%-ACX-312-3-1

Compatible Caliber: .223 .308 Brand: RSI

Part Material: Carbide