Configurable firearm shell casing catching system

A firearm shell casing catching system for collecting casings ejected from a firearm, the firearm having an ejection port and a receiver, the firearm shell casing catching system comprising:

• a mounting assembly selectively attachable to a firearm receiver, the mounting assembly comprising a rear tab, a first side wall defining a first inside surface, a front wall defining a second inside surface, and a second side wall defining a third inside surface, wherein the front wall has a top surface and a bottom surface, wherein the top surface defines a top socket and the bottom surface defines a bottom socket;
• a plurality of shims, wherein each of the plurality of shims is selectably attachable to the mounting assembly, wherein each of the plurality of shims has a body, an upper flange, and a lower flange, wherein the upper flange comprises an upper protrusion, wherein the lower flange comprises a lower protrusion, wherein the upper protrusion is configured to be received by the top socket and the lower protrusion is configured to be received by the lower socket;
• and
• a casing deflector coupled to the mounting assembly, the casing deflector defining a chamber having an upper opening defined by an upper edge, a lower edge, a first side edge, and a second side edge and a lower opening defined by a first edge, a second edge, a third edge, and a fourth edge, wherein the casing deflector comprises an outer wall, the outer wall defining an inner deflecting surface extending between the upper edge and the first edge, wherein a portion of the inner deflecting surface proximate to the upper edge of the upper opening is downwardly angled towards the lower opening.

A firearm shell casing catching system for collecting casings ejected from a firearm, the firearm having an ejection port and a receiver, the firearm shell casing catching system comprising:

• a mounting assembly selectively attachable to a firearm receiver, the mounting assembly comprising a rear tab, a first side wall defining a first inside surface, a front wall defining a second inside surface, and a second side wall defining a third inside surface, wherein the front wall has a top surface and a bottom surface, wherein the top surface defines a top socket and the bottom surface defines a bottom socket;
• a shim selectably attachable to the mounting assembly, having a body, an upper flange, and a lower flange, wherein the upper flange comprises an upper protrusion, wherein the lower flange comprises a lower protrusion, wherein the upper protrusion is configured to be received by the top socket and the lower protrusion is configured to be received by the bottom socket;
• and
• a casing deflector coupled to the mounting assembly, the casing deflector defining a chamber having an upper opening and a lower opening, wherein the casing deflector comprises an outer wall, the outer wall defining an inner deflecting surface extending between an upper edge and an first edge, wherein a first portion of the inner deflecting surface proximate to the upper edge of the upper opening is downwardly angled between about 40 degrees and about 80 degrees.