Polymer firearm receiver

1. A receiver blank comprising: a receiver body comprising a magazine well; and an insert, wherein: the insert is located internal to the receiver body; the insert is manufactured before the receiver body; and the insert must be removed from the receiver body to convert the receiver blank to a firearm receiver; the receiver body and the insert comprise different materials; and the insert comprises a water-soluble material.

2. The receiver blank of claim 1 , wherein the insert comprises at least one protrusion extending away from the receiver body such that the at least one protrusion is visible.

3. The receiver blank of claim 2 , wherein the entirety of the insert other than a portion of the at least one protrusion is not visible because the insert is internal to the receiver body.

4. The receiver blank of claim 1 , wherein the insert comprises a plurality of holes extending at least partially through the insert.

5. The receiver blank of claim 1 , wherein the material of the receiver body and the insert comprises at least one selected from the group of plastic, thermoplastic, nylon, polyetherimide, polyoxymethylene, polytetrafluoroethylene, polyethylene, polypropylene, polyvinyl chloride, polystyrene, or carbon composite.

6. The receiver blank of claim 2 , wherein the at least one protrusion comprises a cylindrical shape with a circular cross section.

7. The receiver blank of claim 1 , wherein: the receiver body comprises at least one material selected from the group of plastic, thermoplastic, nylon, polyetherimide, polyoxymethylene, polytetrafluoroethylene, polyethylene, polypropylene, polyvinyl chloride, polystyrene, or carbon composite.

8. The receiver blank of claim 1 , wherein the shape of the insert approximately corresponds to a fire-control cavity of the firearm receiver.

9. The receiver blank of claim 8 , wherein the insert comprises at least one dimension that is smaller than a corresponding dimension of the fire-control cavity.

10. The receiver blank of claim 1 , wherein the receiver body is a receiver for a handgun.

11. The receiver blank of claim 1 , further comprising a portion for serialization.

12. A method of manufacturing a receiver blank, the method comprising: forming an insert that approximately corresponds to a fire-control cavity of a firearm receiver; forming a receiver body around the insert, wherein: the insert is manufactured before the receiver body; and the insert must be removed from the receiver body to convert the receiver blank to a firearm receiver, wherein the insert comprises a water-soluble material.

13. The method of claim 12 , wherein forming the insert comprises injecting liquified polymer into a first cavity.

14. The method of claim 13 , wherein forming the receiver body comprises injecting liquified polymer into a second cavity.

15. The method of claim 12 , wherein: forming the insert comprises forming at least one protrusion extending from the insert; and forming the receiver body comprises inserting the at least one protrusion into a corresponding feature within a mold for the receiver body.

16. The method of claim 12 , wherein the insert comprises a different color than the receiver body.

17. A receiver blank comprising: a receiver body comprising a magazine well; and an insert, wherein: the insert is located internal to the receiver body; the insert is manufactured before the receiver body; the insert comprises at least one protrusion extending away from both the insert and the receiver body such that the at least one protrusion is visible; the at least one protrusion comprises a cylindrical shape with a circular cross section; and the insert must be removed from the receiver body to convert the receiver blank to a firearm receiver.

18. The receiver blank of claim 17 , wherein the receiver body and the insert comprise the same material.

19. The receiver blank of claim 17 , wherein: the receiver body comprises at least one material selected from the group of plastic, thermoplastic, nylon, polyetherimide, polyoxymethylene, polytetrafluoroethylene, polyethylene, polypropylene, polyvinyl chloride, polystyrene, or carbon composite; and the insert comprises a water-soluble material.

20. The receiver blank of claim 17 , wherein the insert comprises at least one material selected from the group of a polyvinyl alcohol thermoplastic, a polyvinyl acetal, or a water-soluble synthetic polymer.