Screw commit history.

code/modules/projectiles/ammunition/_ammunition.dm

@@ -7,7 +7,7 @@
 	slot_flags = ITEM_SLOT_BELT
 	throwforce = 0
 	w_class = WEIGHT_CLASS_TINY
-	materials = list(MAT_METAL = 500)
+	custom_materials = list(/datum/material/iron = 500)
 	var/fire_sound = null						//What sound should play when this ammo is fired
 	var/caliber = list()							//Which kind of guns it can be loaded into
 	var/projectile_type = null					//The bullet type to create when New() is called

code/modules/projectiles/ammunition/ballistic/shotgun.dm

@@ -6,14 +6,14 @@
 	icon_state = "blshell"
 	caliber = "shotgun"
 	projectile_type = /obj/item/projectile/bullet/shotgun_slug
-	materials = list(MAT_METAL=4000)
+	custom_materials = list(/datum/material/iron=4000)
 
 /obj/item/ammo_casing/shotgun/beanbag
 	name = "beanbag slug"
 	desc = "A weak beanbag slug for riot control."
 	icon_state = "bshell"
 	projectile_type = /obj/item/projectile/bullet/shotgun_beanbag
-	materials = list(MAT_METAL=250)
+	custom_materials = list(/datum/material/iron=250)
 
 /obj/item/ammo_casing/shotgun/incendiary
 	name = "incendiary slug"
@@ -34,7 +34,7 @@
 	desc = "A stunning taser slug."
 	icon_state = "stunshell"
 	projectile_type = /obj/item/projectile/bullet/shotgun_stunslug
-	materials = list(MAT_METAL=250)
+	custom_materials = list(/datum/material/iron=250)
 
 /obj/item/ammo_casing/shotgun/meteorslug
 	name = "meteorslug shell"
@@ -71,14 +71,14 @@
 	projectile_type = /obj/item/projectile/bullet/pellet/shotgun_rubbershot
 	pellets = 6
 	variance = 25
-	materials = list(MAT_METAL=4000)
+	custom_materials = list(/datum/material/iron=4000)
 
 /obj/item/ammo_casing/shotgun/improvised
 	name = "improvised shell"
 	desc = "An extremely weak shotgun shell with multiple small pellets made out of metal shards."
 	icon_state = "improvshell"
 	projectile_type = /obj/item/projectile/bullet/pellet/shotgun_improvised
-	materials = list(MAT_METAL=250)
+	custom_materials = list(/datum/material/iron=250)
 	pellets = 10
 	variance = 25
 

code/modules/projectiles/ammunition/caseless/foam.dm

@@ -5,7 +5,7 @@
 	caliber = "foam_force"
 	icon = 'icons/obj/guns/toy.dmi'
 	icon_state = "foamdart"
-	materials = list(MAT_METAL = 11.25)
+	custom_materials = list(/datum/material/iron = 11.25)
 	harmful = FALSE
 	var/modified = FALSE
 
@@ -62,4 +62,4 @@
 	desc = "Whose smart idea was it to use toys as crowd control? Ages 18 and up."
 	projectile_type = /obj/item/projectile/bullet/reusable/foam_dart/riot
 	icon_state = "foamdart_riot"
-	materials = list(MAT_METAL = 1125)
+	custom_materials = list(/datum/material/iron = 1125)