Firearm receiver assemblies

1 . A firearm receiver assembly comprising:

a receiver body comprising a plurality of cavities; and

a plurality of rails, wherein:

each of the plurality of rails is disposed in one of the plurality of cavities;

each of the plurality of rails comprises at least one retaining feature; and

the at least one retaining feature comprises a protrusion that penetrates an interior portion of the corresponding cavity.

2 . The firearm receiver assembly of claim 1 , wherein at least a portion of each of the plurality of rails is metallic.

3 . The firearm receiver assembly of claim 1 , wherein at least a portion of the receiver body comprises a polymer material.

4 . The firearm receiver assembly of claim 1 , wherein engagement of the at least one retaining feature with the receiver body permanently attaches the corresponding rail relative to the receiver body.

5 . The firearm receiver assembly of claim 1 , wherein at least one of the plurality of rails includes multiple parts.

6 . The firearm receiver assembly of claim 1 , wherein at least one of the plurality of cavities includes an upper opening and a lower opening.

7 . The firearm receiver assembly of claim 1 , wherein:

the plurality of rails comprises two front rails and at least one rear rail;

each front rail comprises a first member and a second member;

the first member comprises a slide interface portion designed to interface with a slide assembly of a handgun; and

the second member comprises at least one retaining feature.

8 . The firearm receiver assembly of claim 7 , wherein the at least one retaining feature comprises a protrusion that penetrates the interior of the corresponding cavity.

9 . The firearm receiver assembly of claim 1 , wherein:

the plurality of rails comprises at least one rear rail;

the at least one rear rail comprises a stabilizing feature comprising at least one selected from the group of a notch or a protrusion; and

the stabilizing feature engages a corresponding feature of the receiver body to reduce movement of the rear rail relative to the receiver body.

10 . A handgun receiver assembly comprising:

a receiver body comprising a plurality of cavities;

at least one front rail at least partially disposed in one of the plurality of cavities; and

at least one rear rail at least partially disposed in one of the plurality of cavities, wherein:

the at least one front rail comprises at least one retaining feature that is integral to the at least one front rail; and

engagement of the at least one retaining feature with the receiver body permanently attaches the corresponding rail relative to the receiver body.

11 . The handgun receiver assembly of claim 10 , wherein the at least one front rail comprises a front left rail inserted into a first cavity of the receiver body and a front right rail inserted into a second cavity of the receiver body.

12 . The handgun receiver assembly of claim 10 , wherein:

each at least one front rail comprises a first member and a second member;

the first member comprises a slide interface portion that protrudes out of the top of the appropriate cavity; and

the second member comprises a “L” shape.

13 . The handgun receiver assembly of claim 12 , wherein the second member comprises a protrusion that penetrates the interior of the corresponding cavity.

14 . The handgun receiver assembly of claim 12 , wherein the first member comprises a lower protrusion configured to engage a corresponding shelf in the cavity.

15 . The handgun receiver assembly of claim 10 , wherein at least a portion of the receiver body comprises a polymer material.

16 . The handgun receiver assembly of claim 10 , wherein at least one of the plurality of cavities includes an upper opening and a lower opening.

17 . The handgun receiver assembly of claim 10 , wherein the at least one rear rail comprises a single component with an overall U shape with two slide interface portions.

18 . The handgun receiver assembly of claim 10 , wherein the at least one rear rail comprises:

a hole designed to interface with a pin to locate the at least one rear rail relative to the receiver body; and

a stabilizing feature comprising at least one selected from the group of a notch or a protrusion, wherein the stabilizing feature is configured to engage a corresponding feature of the receiver body to reduce movement of the at least one rear rail relative to the receiver body.

19 . The handgun receiver assembly of claim 10 , wherein the at least one rear rail comprises two internal interface portions that each bend inboard toward a center of the rear rail, wherein the internal interface portions are designed to interface with a trigger housing.

20 . A firearm receiver assembly comprising:

a receiver body comprising a plurality of cavities; and

a plurality of rails, comprising two front rails and at least one rear rail, wherein:

each of the plurality of rails is disposed in one of the plurality of cavities;

each of the plurality of rails comprises at least one retaining feature;

each front rail comprises a first member and a second member;

the first member comprises a slide interface portion designed to interface with a slide assembly of a handgun;

the second member comprises at least one retaining feature; and

the at least one retaining feature comprises a protrusion that penetrates the interior of the corresponding cavity.