FWIW, I've started knocking mags out on emergency reloads with a flagged thumb holding the new magazine. Saves more wear and tear on the magazines and the latch (but not so much for your thumb). In some ways it is more natural because I have a better ideal where my thumb is spatially than the end of the mag at times. Picked it up from Travis Haley's Adaptive Kalash, although Sonny Puzikas may have mentioned it too in BTF2/Fighting with the AK. Sonny does make the point when slapping mags out, go at more of a 30-45 degree upward angle to make it more effective and use the weight of the rifle to help rock the new one in (he doesn't necessarily "break it down into the workspace").
Here's the AK-104, sorry for the crappy pic quality with these quick snapshots. I'll try to get better soon along with its bag system (Emdom TNT GYM-E Bag):
-CNC Warrior Extended 4 piece, blind pinned and welded
-Tech Sights thinner target front post
-RS Regulate BM-1 with Viking Tactics light mount and Jetbeam PC25 light
-RS Regualte AKM with Trijicon TriPower
-US Palm Grip
-Urban ERT E-Rush Sling in two point mode with a County Comm MOLLE Lighter Case for a couple of CR123 and 1/3N batteries
the sun really reflected on that Khaki yellow.
