Adds Extended drum mag and bundle for nuke ops.

code/modules/projectiles/ammunition.dm

@@ -123,6 +123,7 @@
 		if(keep)
 			stored_ammo.Insert(1,b)
 		update_mat_value()
+		update_icon()
 		return b
 
 /obj/item/ammo_box/proc/give_round(obj/item/ammo_casing/R, replace_spent = 0)

code/modules/projectiles/ammunition/magazines.dm

@@ -380,10 +380,7 @@
 	origin_tech = "combat=3;syndicate=1"
 	caliber = "shotgun"
 	max_ammo = 8
-
-/obj/item/ammo_box/magazine/m12g/update_icon()
-	..()
-	icon_state = "[initial(icon_state)]-[Ceiling(ammo_count(0)/8)*8]"
+	multiple_sprites = 2
 
 /obj/item/ammo_box/magazine/m12g/buckshot
 	name = "shotgun magazine (12g buckshot slugs)"
@@ -411,6 +408,24 @@
 	icon_state = "m12gbc"
 	ammo_type = /obj/item/ammo_casing/shotgun/breaching
 
+/obj/item/ammo_box/magazine/m12g/XtrLrg
+	name = "\improper XL shotgun magazine (12g slugs)"
+	desc = "An extra large drum magazine."
+	icon_state = "m12gXlSl"
+	w_class = WEIGHT_CLASS_NORMAL
+	ammo_type = /obj/item/ammo_casing/shotgun
+	max_ammo = 16
+
+/obj/item/ammo_box/magazine/m12g/XtrLrg/buckshot
+	name = "\improper XL shotgun magazine (12g buckshot)"
+	icon_state = "m12gXlBs"
+	ammo_type = /obj/item/ammo_casing/shotgun/buckshot
+
+/obj/item/ammo_box/magazine/m12g/XtrLrg/dragon
+	name = "\improper XL shotgun magazine (12g dragon's breath)"
+	icon_state = "m12gXlDb"
+	ammo_type = /obj/item/ammo_casing/shotgun/incendiary/dragonsbreath
+
 /obj/item/ammo_box/magazine/toy
 	name = "foam force META magazine"
 	ammo_type = /obj/item/ammo_casing/caseless/foam_dart

code/modules/projectiles/guns/projectile/automatic.dm

@@ -275,13 +275,27 @@
 	if(magazine)
 		overlays.Cut()
 		overlays += "[magazine.icon_state]"
-		return
+		if(istype(magazine, /obj/item/ammo_box/magazine/m12g/XtrLrg))
+			w_class = WEIGHT_CLASS_BULKY
+		else
+			w_class = WEIGHT_CLASS_NORMAL
+	else
+		w_class = WEIGHT_CLASS_NORMAL
 
 /obj/item/gun/projectile/automatic/shotgun/bulldog/update_icon()
 	overlays.Cut()
 	update_magazine()
 	icon_state = "bulldog[chambered ? "" : "-e"]"
 
+/obj/item/gun/projectile/automatic/shotgun/bulldog/attackby(var/obj/item/A as obj, mob/user as mob, params)
+	if(istype(A, /obj/item/ammo_box/magazine/m12g/XtrLrg))
+		if(istype(loc, /obj/item/storage))	// To prevent inventory exploits
+			var/obj/item/storage/Strg = loc
+			if(Strg.max_w_class < WEIGHT_CLASS_BULKY)
+				to_chat(user, "<span class='warning'>You can't reload [src], with a XL mag, while it's in a normal bag.</span>")
+				return
+	return ..()
+
 /obj/item/gun/projectile/automatic/shotgun/bulldog/afterattack(atom/target as mob|obj|turf|area, mob/living/user as mob|obj, flag)
 	..()
 	empty_alarm()