support for partially-filled/empty guns which still have magazines

_maps/RandomRuins/LavaRuins/lavaland_surface_wrecked_factory.dmm

@@ -846,7 +846,7 @@
 	dir = 4
 	},
 /obj/item/ammo_box/magazine/co9mm{
-	start_empty = 1
+	percent_fill = 0
 	},
 /obj/item/ammo_casing/c9mm{
 	icon_state = "pistol-brass-empty";
@@ -2714,7 +2714,7 @@
 	dir = 1
 	},
 /obj/item/ammo_box/magazine/smgm9mm{
-	start_empty = 1
+	percent_fill = 0
 	},
 /obj/item/gun/ballistic/automatic/smg/proto,
 /turf/open/floor/plasteel/dark,
@@ -4361,7 +4361,7 @@
 "RC" = (
 /obj/effect/turf_decal/siding/white,
 /obj/item/ammo_box/magazine/m10mm{
-	start_empty = 1
+	percent_fill = 0
 	},
 /obj/item/ammo_casing/c10mm{
 	icon_state = "pistol-steel-empty";
@@ -5014,7 +5014,7 @@
 /obj/effect/decal/cleanable/blood/old,
 /obj/effect/turf_decal/siding/white,
 /obj/item/ammo_box/magazine/m10mm{
-	start_empty = 1
+	percent_fill = 0
 	},
 /turf/open/floor/concrete/pavement/lava,
 /area/overmap_encounter/planetoid/lava/explored)

_maps/RandomRuins/SpaceRuins/spacemall.dmm

@@ -12885,7 +12885,7 @@
 /obj/item/ammo_box/magazine/co9mm{
 	pixel_x = 6;
 	pixel_y = 4;
-	start_empty = 1
+	percent_fill = 0
 	},
 /turf/open/floor/plasteel,
 /area/ruin/space/has_grav/spacemall/shop2)

code/modules/cargo/packs/ammo.dm

@@ -1,6 +1,15 @@
 /datum/supply_pack/ammo
 	group = "Ammunition"
 	crate_type = /obj/structure/closet/crate/secure/gear
+	var/start_empty = FALSE
+
+/datum/supply_pack/ammo/fill(obj/structure/closet/crate/C)
+	. = ..()
+	if(!start_empty)
+		return .
+	for(var/obj/item/ammo_box/magazine/clippy in C.contents)
+		var/list/boolets = clippy.ammo_list(TRUE)
+		QDEL_LIST(boolets)
 
 /*
 		Pistol ammo

code/modules/cargo/packs/gun.dm

@@ -1,6 +1,14 @@
 /datum/supply_pack/gun
 	group = "Guns"
 	crate_type = /obj/structure/closet/crate/secure/weapon
+	var/start_empty = FALSE
+
+/datum/supply_pack/gun/fill(obj/structure/closet/crate/C)
+	. = ..()
+	if(!start_empty)
+		return .
+	for(var/obj/item/gun/thegun in C.contents)
+		thegun.set_empty()
 
 /*
 		Pistols

code/modules/projectiles/boxes_magazines/_box_magazine.dm

@@ -29,14 +29,14 @@
 	var/multiload = TRUE
 	///Whether or not an ammo box skips the do_after process (e.g. speedloaders)
 	var/instant_load = FALSE
-	///Whether the magazine should start with nothing in it
-	var/start_empty = FALSE
+	///Amount of our max ammo we should start with, as a multiplier. Can be overridden by Initialize.
+	var/percent_fill = 1
 	///cost of all the bullets in the magazine/box
 	var/list/bullet_cost
 	///cost of the materials in the magazine/box itself
 	var/list/base_cost
 
-/obj/item/ammo_box/Initialize()
+/obj/item/ammo_box/Initialize(mapload, ammo_mod = percent_fill)
 	. = ..()
 	if(!base_icon_state)
 		base_icon_state = icon_state
@@ -48,8 +48,9 @@
 			material_amount *= 0.90 // 10% for the container
 			material_amount /= max_ammo
 			LAZYSET(bullet_cost, material, material_amount)
-	if(!start_empty)
-		for(var/i = 1, i <= max_ammo, i++)
+	if(ammo_mod)
+		var/bullets = round(max_ammo * clamp(ammo_mod, 0, 1), 1)
+		for(var/i = 1, i <= bullets, i++)
 			stored_ammo += new ammo_type(src)
 	update_ammo_count()
 

code/modules/projectiles/boxes_magazines/generic_ammo_box.dm

@@ -2,7 +2,7 @@
 	name = "generic ammo box"
 	desc = "A generic, unbranded box of ammo. It doesn't have great capacity, but it can hold a variety of different calibers."
 	max_ammo = 20
-	start_empty = TRUE
+	percent_fill = 0
 	icon_state = "generic-ammo"
 	/// Does the box currently have an ammo type set?
 	var/ammo_set = FALSE

code/modules/projectiles/boxes_magazines/internal/misc.dm

@@ -2,5 +2,5 @@
 	name = "bowstring"
 	ammo_type = /obj/item/ammo_casing/caseless/arrow
 	max_ammo = 1
-	start_empty = TRUE
+	percent_fill = 0
 	caliber = "arrow"

code/modules/projectiles/boxes_magazines/internal/shotgun.dm

@@ -34,7 +34,7 @@
 	name = "improvised shotgun internal magazine"
 	ammo_type = /obj/item/ammo_casing/shotgun/improvised
 	max_ammo = 1
-	start_empty = TRUE
+	percent_fill = 0
 
 /obj/item/ammo_box/magazine/internal/shot/riot
 	name = "riot shotgun internal magazine"

code/modules/projectiles/gun.dm

@@ -89,6 +89,9 @@
 	var/knife_x_offset = 0
 	var/knife_y_offset = 0
 
+	///Amount of max ammo our magazine or cell spawns with, as a multiplier. Used by energy/ballistic guns
+	var/percent_fill = 1
+
 	var/ammo_x_offset = 0 //used for positioning ammo count overlay on sprite
 	var/ammo_y_offset = 0
 	var/flight_x_offset = 0
@@ -160,6 +163,9 @@
 	. = ..()
 	AddComponent(/datum/component/two_handed)
 
+/// Used to empty this gun's magazine/cell/etc post-spawn
+/obj/item/gun/proc/set_empty()
+
 /// triggered on wield of two handed item
 /obj/item/gun/proc/on_wield(obj/item/source, mob/user)
 	wielded = TRUE

code/modules/projectiles/guns/ballistic.dm

@@ -99,18 +99,25 @@
 	///If we have the 'snowflake mechanic,' how long should it take to reload?
 	var/tactical_reload_delay  = 1 SECONDS
 
-/obj/item/gun/ballistic/Initialize()
+/obj/item/gun/ballistic/Initialize(mapload, ammo_mod = percent_fill)
 	. = ..()
 	if (!spawnwithmagazine && !ispath(mag_type, /obj/item/ammo_box/magazine/internal))
 		bolt_locked = TRUE
 		update_appearance()
 		return
 	if (!magazine)
-		magazine = new mag_type(src)
+		magazine = new mag_type(src, ammo_mod)
 	if (!spawnwithmagazine)
-		get_ammo_list (drop_all = TRUE)
+		set_empty()
 	chamber_round()
 	update_appearance()
+
+/obj/item/gun/ballistic/set_empty()
+	if(magazine)
+		var/list/L = get_ammo_list(drop_all = TRUE)
+		QDEL_LIST(L)
+	update_appearance()
+
 /obj/item/gun/ballistic/update_icon_state()
 	if(current_skin)
 		icon_state = "[unique_reskin[current_skin]][sawn_off ? "_sawn" : ""]"

code/modules/projectiles/guns/ballistic/revolver.dm

@@ -478,6 +478,7 @@
 	mag_type = /obj/item/ammo_box/magazine/internal/cylinder/rev38
 	obj_flags = UNIQUE_RENAME
 	semi_auto = TRUE //double action
+	spawnwithmagazine = FALSE
 	safety_wording = "safety"
 	unique_reskin = list("Default" = "detective",
 		"Stainless Steel" = "detective_stainless",

code/modules/projectiles/guns/energy.dm

@@ -57,20 +57,23 @@
 /obj/item/gun/energy/get_cell()
 	return cell
 
-/obj/item/gun/energy/Initialize()
+/obj/item/gun/energy/Initialize(mapload, ammo_mod = percent_fill)
 	. = ..()
 	if(cell_type)
 		cell = new cell_type(src)
-	else
-		cell = new(src)
-	if(!dead_cell)
-		cell.give(cell.maxcharge)
+	if(ammo_mod)
+		cell.give(cell.maxcharge * ammo_mod)
 	update_ammo_types()
 	recharge_newshot(TRUE)
 	if(selfcharge)
 		START_PROCESSING(SSobj, src)
 	update_appearance()
 
+/obj/item/gun/energy/set_empty()
+	if(cell)
+		cell.use(cell.maxcharge)
+	update_appearance()
+
 /obj/item/gun/energy/ComponentInitialize()
 	. = ..()
 	AddElement(/datum/element/update_icon_updates_onmob)