diff --git a/code/_onclick/hud/map_popups.dm b/code/_onclick/hud/map_popups.dm
index f711e4af1cc..991e252b146 100644
--- a/code/_onclick/hud/map_popups.dm
+++ b/code/_onclick/hud/map_popups.dm
@@ -53,23 +53,18 @@
 		screen_maps[screen_obj.assigned_map] = list()
 	// NOTE: Possibly an expensive operation
 	var/list/screen_map = screen_maps[screen_obj.assigned_map]
-	if(!screen_map.Find(screen_obj))
-		screen_map += screen_obj
-	if(!screen.Find(screen_obj))
-		screen += screen_obj
+	screen_map |= screen_obj
+	screen |= screen_obj
 
 /**
  * Clears the map of registered screen objects.
- *
- * Not really needed most of the time, as the client's screen list gets reset
- * on relog. any of the buttons are going to get caught by garbage collection
- * anyway. they're effectively qdel'd.
  */
 /client/proc/clear_map(map_name)
-	if(!map_name || !(map_name in screen_maps))
+	if(!map_name || !screen_maps[map_name])
 		return FALSE
 	for(var/atom/movable/screen/screen_obj in screen_maps[map_name])
 		screen_maps[map_name] -= screen_obj
+		screen -= screen_obj
 		if(screen_obj.del_on_map_removal)
 			qdel(screen_obj)
 	screen_maps -= map_name
diff --git a/code/game/machinery/computer/camera.dm b/code/game/machinery/computer/camera.dm
index f60cb7b2df7..614b6382538 100644
--- a/code/game/machinery/computer/camera.dm
+++ b/code/game/machinery/computer/camera.dm
@@ -51,9 +51,9 @@
 	cam_background.del_on_map_removal = FALSE
 
 /obj/machinery/computer/security/Destroy()
-	qdel(cam_screen)
+	QDEL_NULL(cam_screen)
 	QDEL_LIST(cam_plane_masters)
-	qdel(cam_background)
+	QDEL_NULL(cam_background)
 	return ..()
 
 /obj/machinery/computer/security/connect_to_shuttle(obj/docking_port/mobile/port, obj/docking_port/stationary/dock)
diff --git a/code/game/objects/items/devices/spyglasses.dm b/code/game/objects/items/devices/spyglasses.dm
index 6145f7a2091..a1e22d5ffef 100644
--- a/code/game/objects/items/devices/spyglasses.dm
+++ b/code/game/objects/items/devices/spyglasses.dm
@@ -11,7 +11,7 @@
 		return
 	if(!linked_bug)
 		user.audible_message(span_warning("[src] lets off a shrill beep!"))
-	if("spypopup_map" in user.client.screen_maps) //alright, the popup this object uses is already IN use, so the window is open. no point in doing any other work here, so we're good.
+	if(user.client.screen_maps["spypopup_map"]) //alright, the popup this object uses is already IN use, so the window is open. no point in doing any other work here, so we're good.
 		return
 	user.client.setup_popup("spypopup", 3, 3, 2)
 	user.client.register_map_obj(linked_bug.cam_screen)
@@ -78,9 +78,9 @@
 /obj/item/clothing/accessory/spy_bug/Destroy()
 	if(linked_glasses)
 		linked_glasses.linked_bug = null
-	qdel(cam_screen)
+	QDEL_NULL(cam_screen)
 	QDEL_LIST(cam_plane_masters)
-	qdel(tracker)
+	QDEL_NULL(tracker)
 	. = ..()
 
 /obj/item/clothing/accessory/spy_bug/proc/update_view()//this doesn't do anything too crazy, just updates the vis_contents of its screen obj
diff --git a/code/modules/client/preferences.dm b/code/modules/client/preferences.dm
index 592c614e4c3..81f2bc8bfbe 100644
--- a/code/modules/client/preferences.dm
+++ b/code/modules/client/preferences.dm
@@ -376,7 +376,6 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/character_preview_view)
 		qdel(plane_master)
 
 	client?.clear_map(assigned_map)
-	client?.screen -= src
 
 	preferences?.character_preview_view = null
 
diff --git a/code/modules/mob/mob.dm b/code/modules/mob/mob.dm
index 501c4735ee1..d15f912df9b 100644
--- a/code/modules/mob/mob.dm
+++ b/code/modules/mob/mob.dm
@@ -445,34 +445,36 @@
  * [this byond forum post](https://secure.byond.com/forum/?post=1326139&page=2#comment8198716)
  * for why this isn't atom/verb/examine()
  */
-/mob/verb/examinate(atom/A as mob|obj|turf in view()) //It used to be oview(12), but I can't really say why
+/mob/verb/examinate(atom/examinify as mob|obj|turf in view()) //It used to be oview(12), but I can't really say why
 	set name = "Examine"
 	set category = "IC"
 
-	if(isturf(A) && !(sight & SEE_TURFS) && !(A in view(client ? client.view : world.view, src)))
+	if(isturf(examinify) && !(sight & SEE_TURFS) && !(examinify in view(client ? client.view : world.view, src)))
 		// shift-click catcher may issue examinate() calls for out-of-sight turfs
 		return
 
-	if(is_blind() && !blind_examine_check(A)) //blind people see things differently (through touch)
+	if(is_blind() && !blind_examine_check(examinify)) //blind people see things differently (through touch)
 		return
 
-	face_atom(A)
+	face_atom(examinify)
 	var/list/result
 	if(client)
 		LAZYINITLIST(client.recent_examines)
-		if(isnull(client.recent_examines[A]) || client.recent_examines[A] < world.time)
-			result = A.examine(src)
-			client.recent_examines[A] = world.time + EXAMINE_MORE_TIME // set the value to when the examine cooldown ends
-			RegisterSignal(A, COMSIG_PARENT_QDELETING, .proc/clear_from_recent_examines, override=TRUE) // to flush the value if deleted early
-			addtimer(CALLBACK(src, .proc/clear_from_recent_examines, A), EXAMINE_MORE_TIME)
-			handle_eye_contact(A)
+		var/ref_to_atom = ref(examinify)
+		var/examine_time = client.recent_examines[ref_to_atom]
+
+		if(isnull(examine_time) || examine_time < world.time)
+			result = examinify.examine(src)
+			client.recent_examines[ref_to_atom] = world.time + EXAMINE_MORE_TIME // set the value to when the examine cooldown ends
+			addtimer(CALLBACK(src, .proc/clear_from_recent_examines, ref_to_atom), EXAMINE_MORE_TIME)
+			handle_eye_contact(examinify)
 		else
-			result = A.examine_more(src)
+			result = examinify.examine_more(src)
 	else
-		result = A.examine(src) // if a tree is examined but no client is there to see it, did the tree ever really exist?
+		result = examinify.examine(src) // if a tree is examined but no client is there to see it, did the tree ever really exist?
 
 	to_chat(src, "<span class='infoplain'>[result.Join("\n")]</span>")
-	SEND_SIGNAL(src, COMSIG_MOB_EXAMINATE, A)
+	SEND_SIGNAL(src, COMSIG_MOB_EXAMINATE, examinify)
 
 
 /mob/proc/blind_examine_check(atom/examined_thing)
@@ -508,7 +510,7 @@
 
 	/// how long it takes for the blind person to find the thing they're examining
 	var/examine_delay_length = rand(1 SECONDS, 2 SECONDS)
-	if(client?.recent_examines && client?.recent_examines[examined_thing]) //easier to find things we just touched
+	if(client?.recent_examines && client?.recent_examines[ref(examined_thing)]) //easier to find things we just touched
 		examine_delay_length = 0.33 SECONDS
 	else if(isobj(examined_thing))
 		examine_delay_length *= 1.5
@@ -528,13 +530,11 @@
 	return TRUE
 
 
-/mob/proc/clear_from_recent_examines(atom/A)
+/mob/proc/clear_from_recent_examines(ref_to_clear)
 	SIGNAL_HANDLER
-
 	if(!client)
 		return
-	UnregisterSignal(A, COMSIG_PARENT_QDELETING)
-	LAZYREMOVE(client.recent_examines, A)
+	LAZYREMOVE(client.recent_examines, ref_to_clear)
 
 /**
  * handle_eye_contact() is called when we examine() something. If we examine an alive mob with a mind who has examined us in the last second within 5 tiles, we make eye contact!
diff --git a/code/modules/modular_computers/file_system/programs/secureye.dm b/code/modules/modular_computers/file_system/programs/secureye.dm
index d2d7590cb18..0ece187e5a4 100644
--- a/code/modules/modular_computers/file_system/programs/secureye.dm
+++ b/code/modules/modular_computers/file_system/programs/secureye.dm
@@ -54,9 +54,9 @@
 	cam_background.del_on_map_removal = FALSE
 
 /datum/computer_file/program/secureye/Destroy()
-	qdel(cam_screen)
+	QDEL_NULL(cam_screen)
 	QDEL_LIST(cam_plane_masters)
-	qdel(cam_background)
+	QDEL_NULL(cam_background)
 	return ..()
 
 /datum/computer_file/program/secureye/ui_interact(mob/user, datum/tgui/ui)
diff --git a/code/modules/projectiles/ammunition/caseless/_caseless.dm b/code/modules/projectiles/ammunition/caseless/_caseless.dm
index 6718e88a872..ef813060b13 100644
--- a/code/modules/projectiles/ammunition/caseless/_caseless.dm
+++ b/code/modules/projectiles/ammunition/caseless/_caseless.dm
@@ -4,12 +4,14 @@
 	heavy_metal = FALSE
 
 /obj/item/ammo_casing/caseless/fire_casing(atom/target, mob/living/user, params, distro, quiet, zone_override, spread, atom/fired_from)
-	if (..()) //successfully firing
-		moveToNullspace()
-		QDEL_NULL(src)
-		return TRUE
-	else
+	if (!..()) //failed firing
 		return FALSE
+	if(istype(fired_from, /obj/item/gun))
+		var/obj/item/gun/shot_from = fired_from
+		if(shot_from.chambered == src)
+			shot_from.chambered = null //Nuke it. Nuke it now.
+	qdel(src)
+	return TRUE
 
 /obj/item/ammo_casing/caseless/update_icon_state()
 	. = ..()
diff --git a/code/modules/projectiles/guns/ballistic.dm b/code/modules/projectiles/guns/ballistic.dm
index a6fa9700178..fd5b969c31d 100644
--- a/code/modules/projectiles/guns/ballistic.dm
+++ b/code/modules/projectiles/guns/ballistic.dm
@@ -213,12 +213,15 @@
 /obj/item/gun/ballistic/handle_chamber(empty_chamber = TRUE, from_firing = TRUE, chamber_next_round = TRUE)
 	if(!semi_auto && from_firing)
 		return
-	var/obj/item/ammo_casing/AC = chambered //Find chambered round
-	if(istype(AC)) //there's a chambered round
-		if(casing_ejector || !from_firing)
-			AC.forceMove(drop_location()) //Eject casing onto ground.
-			AC.bounce_away(TRUE)
-			SEND_SIGNAL(AC, COMSIG_CASING_EJECTED)
+	var/obj/item/ammo_casing/casing = chambered //Find chambered round
+	if(istype(casing)) //there's a chambered round
+		if(QDELING(casing))
+			stack_trace("Trying to move a qdeleted casing of type [casing.type]!")
+			chambered = null
+		else if(casing_ejector || !from_firing)
+			casing.forceMove(drop_location()) //Eject casing onto ground.
+			casing.bounce_away(TRUE)
+			SEND_SIGNAL(casing, COMSIG_CASING_EJECTED)
 			chambered = null
 		else if(empty_chamber)
 			chambered = null