New mod background plus some minor changes to particle effects

Added:
Arbiter semi-auto shotgun and its magazines.

Changed:
PPsh drums bullet capacity increased
M60 ammo boxes are once more medium sized items

Added:
Saiga 12 shotgun alongside its regular magazine and extended magazine variants of slug and buckshot shells.

Changed:
M60 ammo boxes fit in backpacks like other machine gun ammo to be less of an annoyance carrying it with you

Added:
Striker automatic shotgun and 2 drum magazines for it, buckshot and slug

Added:
KSG-12 shotgun
fragmentation shotgun shells
high-explosive shotgun shells

Changed:
Shotgun shells now require some steel instead of the vanilla shotgun shells for crafting.

Added:
KS-23 shotgun

Changed:
Slightly reduced the sell/purchase price of some shotguns

Added:
Ithaca 37 pump shotgun

Changed:
Most firearms and ammunition got reduced in both purchase and selling price, paying over 1000mk for some guns was just too much, they aren't cheap but shouldn't be overpriced now.
You can't mass produce cheap guns and sell them for more than what their components would have been worth now though.

SPAS-12 should be held by humans better now

Added:
SPAS-12 shotgun

Changed:
Mg42 can now hold a flashlight, improved casing effect (casings won't fly that high in the air)