Hammer-Extruded from 7075 Aluminum, and then tempered to T6 and stress-relieved prior to machining. Our 6-Position Receiver Extension is Hardcoat Anodized per MIL-A-8625, (Type 3, Class 2) and has a dry-film lubed bore, which will aid in preserving the part for the duration of the weapon.
Liberally grease the threads with Aeroshell64, and then run the receiver extension in, out, in your lower receiver so as to properly coat all threads with grease. Use a Geissele Reaction block if you have one, or clamp lower receiver into vise block using vise block soft-jaws, or wood blocks. If you do not have a vise; we recommend taking your parts to a competent M16/M4/AR15 armorer at a shop.