How does the trigger mechanism on a pintle-mounted machine gun work? I'm thinking of a classic Browning 50. on a tank turret, but really any pintle-mounted machine gun with the two handles at the back. I've never understood those.
I'm going to use the great World of Guns: Gun Disassembly to illustrate what I mean, and this is specific to the M2 Browning.
For years, I thought the handles themselves had to be, somehow, connected to the firing mechanism because this is obviously where you're supposed to grip it. I just never found out the connection between the gripping and the shooting. My (child) mind at the time thought maybe if you gripped or squeezed the grips hard enough, it'd fire.
Then I realized the vaguely V-shaped metal tab within reach is the trigger. (pic 1) You press down on it with either or both thumbs, this is what releases the hammer.
After that, it made sense. It's like a gigantic bolt (pic 2), not too different from other self-loading systems. Though the M2 specifically does something cool (pic 3); the bolt system holds onto both the current (chambered) cartridge and the next shot. When the current shot is fired, the same bolt both ejects the spent casing and rips the next round from the belt. Then as the bolt moves forward, it transfers it to the chamber, then grabs onto the next cartridge, ready to be ripped out of the belt.