The components necessary to assemble or repair a specific variant of a firearm, chambered primarily in 5.56x45mm NATO, are often offered in a collection. These collections typically include essential elements such as the bolt carrier group, trigger assembly, and furniture, excluding the receiver, which is generally considered the regulated portion of the firearm. A complete set facilitates either the construction of a functional firearm or the refurbishment of an existing one, allowing for customization and maintenance.
These collections offer a cost-effective method for individuals to acquire the necessary elements for building or restoring a rifle. Historically, the availability of such collections allowed enthusiasts to create their own firearms or repair those that were damaged, fostering both a practical skill and a deeper understanding of the weapon’s mechanics. These items have also played a role in historical reenactments and collecting, providing a means to own and understand a piece of military or firearms history.