diff --git a/language.version b/language.version
index 33599029d..b31863cd8 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r249 \cu(Thu  4 Aug 17:58:16 CEST 2022)\c-";
-SWWM_SHORTVER="\cw1.3pre r249 \cu(2022-08-04 17:58:16)\c-";
+SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r250 \cu(Thu  4 Aug 18:17:21 CEST 2022)\c-";
+SWWM_SHORTVER="\cw1.3pre r250 \cu(2022-08-04 18:17:21)\c-";
diff --git a/zscript/items/swwm_ammospawn.zsc b/zscript/items/swwm_ammospawn.zsc
index 3824f6e91..ee8ca2b12 100644
--- a/zscript/items/swwm_ammospawn.zsc
+++ b/zscript/items/swwm_ammospawn.zsc
@@ -1,5 +1,6 @@
 // on-demand ammo spawners
-Mixin Class SWWMOndemandAmmoSpawner
+// Ref class for ammo spawners, used by on-demand replacers
+Class SWWMAmmoSpawner : Inventory abstract
 {
 	Actor dropper;
 	bool enemydrop;
@@ -11,9 +12,11 @@ Mixin Class SWWMOndemandAmmoSpawner
 		return false;
 	}
 
-	override void SpawnAmmo()
+	abstract Class<Actor> PickAmmo( bool enemydrop = false );
+
+	void SpawnAmmo()
 	{
-		let ac = PickAmmo();
+		let ac = PickAmmo(enemydrop);
 		if ( !ac ) return;
 		let a = Spawn(ac,pos);
 		if ( enemydrop )
@@ -35,16 +38,41 @@ Mixin Class SWWMOndemandAmmoSpawner
 		}
 		SWWMUtility.TransferItemProp(self,a);
 	}
-}
 
+	override void PostBeginPlay()
+	{
+		SpawnAmmo();
+		ClearCounters();
+		Destroy();
+	}
+
+	override bool CanPickup( Actor toucher )
+	{
+		return false;
+	}
+
+	override bool TryPickup( in out Actor toucher )
+	{
+		return false;
+	}
+
+	default
+	{
+		+NOGRAVITY;
+		+NOBLOCKMAP;
+		+NOINTERACTION;
+		+NOTELEPORT;
+		+DONTSPLASH;
+		+DONTGIB;
+		-SPECIAL;
+	}
+}
 Class SWWMShellAmmoSmall : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = (SWWMUtility.ItemExists('Spreadgun')||SWWMUtility.ItemExists('Wallbuster')),
-			bex = (SWWMUtility.ItemExists('PuntzerBeta')||SWWMUtility.ItemExists('PuntzerGamma'));
+		bool aex = (SWWMUtility.ItemExists('Spreadgun',ownedonly:enemydrop)||SWWMUtility.ItemExists('Wallbuster',ownedonly:enemydrop)),
+			bex = (SWWMUtility.ItemExists('PuntzerBeta',ownedonly:enemydrop)||SWWMUtility.ItemExists('PuntzerGamma',ownedonly:enemydrop));
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SMW05SmallAmmo':'SMW05Ammo3';
 		switch( Random[Replacements](0,9) )
@@ -67,12 +95,10 @@ Class SWWMShellAmmoSmall : SWWMAmmoSpawner
 }
 Class SWWMShellAmmoBig : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = (SWWMUtility.ItemExists('Spreadgun')||SWWMUtility.ItemExists('Wallbuster')),
-			bex = (SWWMUtility.ItemExists('PuntzerBeta')||SWWMUtility.ItemExists('PuntzerGamma'));
+		bool aex = (SWWMUtility.ItemExists('Spreadgun',ownedonly:enemydrop)||SWWMUtility.ItemExists('Wallbuster',ownedonly:enemydrop)),
+			bex = (SWWMUtility.ItemExists('PuntzerBeta',ownedonly:enemydrop)||SWWMUtility.ItemExists('PuntzerGamma',ownedonly:enemydrop));
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SMW05SmallAmmo':'SMW05BigAmmo';
 		switch( Random[Replacements](0,14) )
@@ -101,21 +127,19 @@ Class SWWMShellAmmoBig : SWWMAmmoSpawner
 }
 Class SWWMClipAmmoSmall : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
 		if ( !Random[Replacements](0,4) )
 		{
-			bool aex = SWWMUtility.ItemExists('Eviscerator'),
-				bex = SWWMUtility.ItemExists('HeavyMahSheenGun');
+			bool aex = SWWMUtility.ItemExists('Eviscerator',ownedonly:enemydrop),
+				bex = SWWMUtility.ItemExists('HeavyMahSheenGun',ownedonly:enemydrop);
 			if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 				return Random[Replacements](0,2)?'SheenAmmo3':'SheenSmallAmmo';
 			if ( aex )
 				return 'EvisceratorShell';
 		}
-		bool aex = (SWWMUtility.ItemExists('Spreadgun')||SWWMUtility.ItemExists('Wallbuster')),
-			bex = (SWWMUtility.ItemExists('PuntzerBeta')||SWWMUtility.ItemExists('PuntzerGamma'));
+		bool aex = (SWWMUtility.ItemExists('Spreadgun',ownedonly:enemydrop)||SWWMUtility.ItemExists('Wallbuster',ownedonly:enemydrop)),
+			bex = (SWWMUtility.ItemExists('PuntzerBeta',ownedonly:enemydrop)||SWWMUtility.ItemExists('PuntzerGamma',ownedonly:enemydrop));
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SMW05Ammo':'SMW05Ammo2';
 		return Random[Replacements](0,1)?'RedShell':'GreenShell';
@@ -124,12 +148,10 @@ Class SWWMClipAmmoSmall : SWWMAmmoSpawner
 // special for chaingun ammo drops
 Class SWWMClipAmmoMed : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Eviscerator'),
-			bex = SWWMUtility.ItemExists('HeavyMahSheenGun');
+		bool aex = SWWMUtility.ItemExists('Eviscerator',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('HeavyMahSheenGun',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,1)?'SheenAmmo3':'SheenSmallAmmo';
 		return Random[Replacements](0,1)?'EvisceratorShell':'EvisceratorShell2';
@@ -137,12 +159,10 @@ Class SWWMClipAmmoMed : SWWMAmmoSpawner
 }
 Class SWWMClipAmmoBig : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Eviscerator'),
-			bex = SWWMUtility.ItemExists('HeavyMahSheenGun');
+		bool aex = SWWMUtility.ItemExists('Eviscerator',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('HeavyMahSheenGun',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SheenSmallAmmo':'SheenBigAmmo';
 		return Random[Replacements](0,5)?'EvisceratorShell':Random[Replacements](0,2)?'EvisceratorShell2':'EvisceratorShell3';
@@ -150,12 +170,10 @@ Class SWWMClipAmmoBig : SWWMAmmoSpawner
 }
 Class SWWMBlastAmmoSmall : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Eviscerator'),
-			bex = SWWMUtility.ItemExists('HeavyMahSheenGun');
+		bool aex = SWWMUtility.ItemExists('Eviscerator',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('HeavyMahSheenGun',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SheenAmmo3':'SheenSmallAmmo';
 		return 'EvisceratorShell';
@@ -163,12 +181,10 @@ Class SWWMBlastAmmoSmall : SWWMAmmoSpawner
 }
 Class SWWMBlastAmmoBig : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Eviscerator'),
-			bex = SWWMUtility.ItemExists('HeavyMahSheenGun');
+		bool aex = SWWMUtility.ItemExists('Eviscerator',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('HeavyMahSheenGun',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,2)?'SheenSmallAmmo':'SheenBigAmmo';
 		return Random[Replacements](0,2)?'EvisceratorShell':Random[Replacements](0,1)?'EvisceratorShell2':'EvisceratorShell3';
@@ -176,24 +192,20 @@ Class SWWMBlastAmmoBig : SWWMAmmoSpawner
 }
 Class SWWMRocketAmmoSmall : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Hellblazer'),
-			bex = SWWMUtility.ItemExists('Quadravol');
+		bool aex = SWWMUtility.ItemExists('Hellblazer',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('Quadravol',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) ) return 'QuadravolAmmo';
 		return Random[Replacements](0,2)?'HellblazerMissiles':'HellblazerCrackshots';
 	}
 }
 Class SWWMRocketAmmoBig : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
-		bool aex = SWWMUtility.ItemExists('Hellblazer'),
-			bex = SWWMUtility.ItemExists('Quadravol');
+		bool aex = SWWMUtility.ItemExists('Hellblazer',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('Quadravol',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 			return Random[Replacements](0,4)?'QuadravolAmmo2':'QuadravolAmmo3';
 		switch ( Random[Replacements](0,11) )
@@ -219,35 +231,31 @@ Class SWWMRocketAmmoBig : SWWMAmmoSpawner
 }
 Class SWWMCellAmmoSmall : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
 		if ( !Random[Replacements](0,2) )
 		{
 			if ( !Random[Replacements](0,3) )
 			{
-				bool aex = SWWMUtility.ItemExists('CandyGun'),
-					bex = SWWMUtility.ItemExists('MisterRifle');
+				bool aex = SWWMUtility.ItemExists('CandyGun',ownedonly:enemydrop),
+					bex = SWWMUtility.ItemExists('MisterRifle',ownedonly:enemydrop);
 				if ( (!aex && bex) || (!Random[Replacements](0,2) && bex) ) return 'MisterGAmmo';
 				if ( aex ) return 'CandyGunBullets';
 			}
-			bool aex = SWWMUtility.ItemExists('SilverBullet'),
-				bex = SWWMUtility.ItemExists('RayKhom');
+			bool aex = SWWMUtility.ItemExists('SilverBullet',ownedonly:enemydrop),
+				bex = SWWMUtility.ItemExists('RayKhom',ownedonly:enemydrop);
 			if ( (!aex && bex) || (Random[Replacements](0,1) && bex) ) return 'RayBolt2';
 			if ( aex ) return Random[Replacements](0,2)?'SilverBullets':'SilverBullets2';
 		}
-		bool aex = SWWMUtility.ItemExists('Sparkster'),
-			bex = SWWMUtility.ItemExists('ModernSparkster');
+		bool aex = SWWMUtility.ItemExists('Sparkster',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('ModernSparkster',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) ) return Random[Replacements](0,2)?'SparksterBAmmo':'SparksterRAmmo';
 		return 'SparkUnit';
 	}
 }
 Class SWWMCellAmmoBig : SWWMAmmoSpawner
 {
-	Mixin SWWMOndemandAmmoSpawner;
-
-	static Class<Actor> PickAmmo()
+	override Class<Actor> PickAmmo( bool enemydrop )
 	{
 		if ( !Random[Replacements](0,3) )
 		{
@@ -258,8 +266,8 @@ Class SWWMCellAmmoBig : SWWMAmmoSpawner
 		}
 		if ( Random[Replacements](0,1) )
 		{
-			bool aex = SWWMUtility.ItemExists('SilverBullet'),
-				bex = SWWMUtility.ItemExists('RayKhom');
+			bool aex = SWWMUtility.ItemExists('SilverBullet',ownedonly:enemydrop),
+				bex = SWWMUtility.ItemExists('RayKhom',ownedonly:enemydrop);
 			if ( (!aex && bex) || (Random[Replacements](0,1) && bex) ) return Random[Replacements](0,2)?'RayBolt5':'RayAmmo';
 			if ( aex )
 			{
@@ -269,13 +277,13 @@ Class SWWMCellAmmoBig : SWWMAmmoSpawner
 		}
 		if ( !Random[Replacements](0,2) )
 		{
-			bool aex = SWWMUtility.ItemExists('CandyGun'),
-				bex = SWWMUtility.ItemExists('MisterRifle');
+			bool aex = SWWMUtility.ItemExists('CandyGun',ownedonly:enemydrop),
+				bex = SWWMUtility.ItemExists('MisterRifle',ownedonly:enemydrop);
 			if ( (!aex && bex) || (Random[Replacements](0,1) && bex) ) return Random[Replacements](0,2)?'MisterRound5':'MisterAmmo';
 			if ( aex ) return Random[Replacements](0,3)?'CandyGunBullets3':'CandyGunAmmo';
 		}
-		bool aex = SWWMUtility.ItemExists('Sparkster'),
-			bex = SWWMUtility.ItemExists('ModernSparkster');
+		bool aex = SWWMUtility.ItemExists('Sparkster',ownedonly:enemydrop),
+			bex = SWWMUtility.ItemExists('ModernSparkster',ownedonly:enemydrop);
 		if ( (!aex && bex) || (Random[Replacements](0,1) && bex) )
 		{
 			if ( Random[Replacements](0,1) ) return Random[Replacements](0,2)?'SparksterBAmmo2':'SparksterBAmmo3';
diff --git a/zscript/items/swwm_baseammo.zsc b/zscript/items/swwm_baseammo.zsc
index 2add7e55a..8efbda5c7 100644
--- a/zscript/items/swwm_baseammo.zsc
+++ b/zscript/items/swwm_baseammo.zsc
@@ -645,37 +645,3 @@ Class MagAmmo : Inventory abstract
 		Amount = Random[ShellDrop](1,clamp(dropamount,1,maxdrop));
 	}
 }
-
-// Ref class for ammo spawners, used by on-demand replacers
-Class SWWMAmmoSpawner : Inventory abstract
-{
-	virtual void SpawnAmmo() {}
-
-	override void PostBeginPlay()
-	{
-		SpawnAmmo();
-		ClearCounters();
-		Destroy();
-	}
-
-	override bool CanPickup( Actor toucher )
-	{
-		return false;
-	}
-
-	override bool TryPickup( in out Actor toucher )
-	{
-		return false;
-	}
-
-	default
-	{
-		+NOGRAVITY;
-		+NOBLOCKMAP;
-		+NOINTERACTION;
-		+NOTELEPORT;
-		+DONTSPLASH;
-		+DONTGIB;
-		-SPECIAL;
-	}
-}
diff --git a/zscript/utility/swwm_utility.zsc b/zscript/utility/swwm_utility.zsc
index 1a7ba9b33..b038b7465 100644
--- a/zscript/utility/swwm_utility.zsc
+++ b/zscript/utility/swwm_utility.zsc
@@ -2117,7 +2117,9 @@ Class SWWMUtility
 	//  mapstart: this function is being called during map load, so we
 	//            should also check STAT_TRAVELLING inventory
 	//  worldonly: only checks for items that are placed in the world
-	static bool ItemExists( Class<Inventory> itm, Inventory skipme = null, bool mapstart = false, bool worldonly = false )
+	//  ownedonly: only checks for items that are owned by players
+	//             (note that this is mutually exclusive with worldonly)
+	static bool ItemExists( Class<Inventory> itm, Inventory skipme = null, bool mapstart = false, bool worldonly = false, bool ownedonly = false )
 	{
 		let ti = ThinkerIterator.Create(itm);
 		Inventory i;
@@ -2125,6 +2127,7 @@ Class SWWMUtility
 		{
 			if ( i == skipme ) continue;
 			if ( worldonly && i.Owner ) continue;
+			if ( ownedonly && (!i.Owner || !i.Owner.player) ) continue;
 			return true;
 		}
 		if ( worldonly || !mapstart ) return false;
@@ -2132,6 +2135,7 @@ Class SWWMUtility
 		while ( i = Inventory(ti.Next()) )
 		{
 			if ( i == skipme ) continue;
+			if ( ownedonly && (!i.Owner || !i.Owner.player) ) continue;
 			return true;
 		}
 		return false;