Yeah, I always get to No.1 position on the leaderboards before I hit the second lab because I just go out and kill stuff. By then I usually have 2k of 5.45x39mm on me, 1k 5.56x45mm and about 1k 7.62x39mm the last two types just stashed away. I usually keep all my ammo stashed at the bar.
Unless I am using an Uzi as my secondary, I'll keep about 50 9mm or .45 for fml moments. Any other ammunition types i.e. 7.62x51, 7.62x54mmR, and 7.62x25mm I keep stashed at the bar unless I am going to be hunting for awhile. I only bring the MG3 out when I decide to delve into the Red Forest, go into a lab, or go underground in general.
IIRC my favorite weapons to use were the LR-300 fully tricked out with an Uzi/Mac-10 as my secondary. I recall enjoying the PS90 Badaboom for bloodsucker killing too. It is a custom 20rd P90 that only fires buckshot, slow on automatic but it is great.
I always had an Uzi, a LR-300/Ak/M16, and the PS-90 with me, trading off whenever a certain ammo type would get low. Almost kind of like game seasons
Low on AK ammo, grab NATO weapon and dick around in beginning area killing other stuff and bandits.
Tor also gave me this nasty habit of taking every single weapon and weapon variant I don't yet have into my collection. IIRC I'm somewhere in the realm of 64 stashed weapons on my main SHoC save.