The hangar is BASE values.

Imagine it being on casual.

Play a game on casual - check ammo. Play on regular - it is less. Play on intense - it is even more less. Play on extreme - more less. Play on insane - guess what? It's less.

If you want to check damage and stuff - turn on the following values on hit. Yellow is the weak point damage. The rate of fire remains the same, nothing has changed there, DPS appears normal except for some shotguns which I'm assuming is down to the new spread patterns.

Before declaring a confirmed bug, ensure its not a game mechanic. Compare your screenshots to every other difficulty first.

I'll bet you've never had to rely on your sidearm.