Utterly Mad

Been playing Metro:Last Light a bit lately,
Can I just say fuck everything from the ferry section onwards in survival/ranger mode(ammo is hard to come by and no HUD)? I've been using bullets sparingly throughout the game, focusing on sneaking around, now it seems to constantly throw into sections were you have to fight waves of enemies while waiting for something (and their kinda bullet spongy compared to everything before), leaving me with almost nothing for the bosses which show up shortly after and soak up everything else. Can't even use military grade rounds(basically currency in the game) because I have like 4 left after buying all the ammo for the weapons I had.
Somehow there's more claymores than ammo, so I have to place them down and try and get bosses to charge into them head-on.