Forged– When making forged custom AR parts, the forgings are pieces of material that are formed into a shape while at a high temperature, creating exterior features on the final product. This process of impact forming the material forces the grain structure of the aluminum to align with the general shape of the finished product, which provides a stronger finished part than the linear grain structure of billet material.
Billet– The billet uppers are composed of 7075-T6 aluminum; however, some companies still use 6061 aluminum to reduce cost. This process allows the manufacturer to produce unique designs for their upper receivers for sale in low volumes with minimum tooling costs. Even though the linear grain structure of the billet material is not as strong as forging, it is generally more than adequate for standard consumer use and provides cosmetic variety to the custom AR parts marketplace.
Forward Assist – Although the forward assist method of making custom AR parts has generally been considered a necessity in the military community, it seems to be declining in popularity with the civilian consumer. The number of upper receivers and carriers that utilize forward assist are quickly declining year over year. Many consumers are in favor of omitting the forward assist with the benefits of using fewer parts and having an overall lighter weight rifle. The lack of a forward assist also gives the rifle a more sleek, snag-free design that is visually appealing. In the end, personal preference drives whether or not the forward assist is a necessity to the user when designing and producing custom AR parts.