My guess is that he cocked the gun, which chambered a round, and then removed the magazine. He then put another magazine in and assumed there was no round chambered. A common, but fatal, mistake.
Sad, but too often true. Negligent discharge
69 posted on 06/15/2021 4:02:37 PM PDT by COBOL2Java
(Joe Biden is a squinty-eyed turnip brain)