Question about Contextual Ammo Drops

Is there something I'm missing? I read online about people doing daily ops and such and having like thousands of extra ammo. In my experience running a crit commando build I kinda have to be meticulous to even just about break even. Definitely not storing up like thousands of extra bullets.

I was looking a YouTube video and saw a player doing the Seismic activity event and every enemy was dropping between 20-25 10mm ammo. I have never seen that much ammo drop. I mainly use a handmade and a Tesla, and those usually drop around 5-10 in the world, 10-15 in daily ops and expeditions.

Am I missing some kind of stackable bonus? Just not dealing enough damage? Maybe not playing enough hours? I also remember daily ops being much easier months ago, nowadays they've got like permanent armor piercing. I've tried looking through the wikis on how the ammo drops differ between ammo types, but there's not a lot of info.

Any and all advice is welcome, thanks!