How Stuff Works

Here’s my first video on how a the hammer sear interacts with the middle sear in an AF trigger

dont mind the fabrick holding the springs in place…they just tend to jump away and get lost if not tied down

explenation:
the hammer sear is held by the little edge o the second sear…the reason for the oval hole in the hammer sear is to compensate for the tolerances in AF design making sure the sear is pushed as close to the middle sear as possible, the edge of the middle sear is right above the pin holding it…this way its self locking and wont move one it own to let go…but needs the input of the trigger arm.

over time and on some porly produced samples…when the preload is high even on stock guns, it sometimes wont catch or maybe it catches but lets go unexpectedly….this is due to the rounding of the edges where the 2 sears meet….to compensate you can try and square off the edges, or a bit more radical actually filing the gab in the middle sear a little bit deeper, which will make it get a better grip…but it will also mean a bit more sloppy second stage