IP Library › Granted Patent US 12,680,781
Granted Patent B2
US 12,680,781 · App. 19/275,241 · Granted Jul 14, 2026

Modular bullpup firearm

Inventor: Daniel Peng (Dallas, TX)
Assignee: Atlas Engineering LLC
F41C7/00F41A3/66F41A3/72F41A11/02F41A35/06
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Quick Facts
Patent No.
US 12,680,781
App. No.
19/275,241
Filed
Jul 21, 2025
Granted
Jul 14, 2026
Kind
B2
Art Unit
3641
USPC
42/2
Abstract

Provided is a downward ejecting bullpup firearm with a detachable magazine having a downward facing ejection port rearward of a magazine well. A top inspection window is positioned substantially in vertical alignment with the magazine well. A charging handle body has a rear portion and a forward portion and is movable between forward and rearward positions. The rearward portion blocks the inspection window when the charging handle body is in the forward position and the forward portion has a through-opening that substantially aligns with the inspection window when the charging handle body is in the rearward position.

Claims (9)

1 . A downward ejecting bullpup firearm with a detachable magazine, comprising:

a downward facing ejection port rearward of a magazine well;

a top inspection window positioned substantially in line with the magazine well;

a charging handle body including a rear portion and a forward portion and being movable between forward and rearward positions, the rearward portion blocking the inspection window when the charging handle body is in the forward position and the forward portion including a through-opening that substantially aligns with the inspection window when the charging handle body is in the rearward position.

2 . The firearm of claim 1 , having separable upper and lower receiver bodies.

3 . The firearm of claim 2 , wherein the lower receiver body includes an exchangeable magazine well module, the magazine well module including a housing removably connectable to the lower receiver body that is configured to accept a detachable ammunition magazine and carrying a bolt catch member and a magazine catch member.

4 . The firearm of claim 3 , wherein the bolt catch member and magazine catch member are controlled from a remote position via linkages.

5 . The firearms of claim 4 , wherein the linkages are separable into first and second parts, the first part being part of the magazine well module and the second part being carried by the lower receiver body.

6 . The firearm of claim 5 , wherein the first and second linkage parts are detachably connectable upon insertion and removal of the magazine well module for the lower receiver body.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 22, 2025
From: PENG, DANIEL
To: ATLAS ENGINEERING LLC
Reel/Frame 071784/0180 →
Continuity (2)
Continuation In Part 18952059 · Nov 19, 2024
Related Publication 20260139923A1 · May 21, 2026
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