diff --git a/src/b_think.cpp b/src/b_think.cpp
index 1501a03ac..7ce276aa0 100644
--- a/src/b_think.cpp
+++ b/src/b_think.cpp
@@ -21,7 +21,6 @@
 #include "d_event.h"
 #include "d_player.h"
 #include "vectors.h"
-#include "a_ammo.h"
 
 static FRandom pr_botmove ("BotMove");
 
@@ -346,12 +345,12 @@ void DBot::WhatToGet (AActor *item)
 			}
 		}
 	}
-	else if (item->IsKindOf (RUNTIME_CLASS(AAmmo)))
+	else if (item->IsKindOf (PClass::FindActor(NAME_Ammo)))
 	{
-		AAmmo *ammo = static_cast<AAmmo *> (item);
-		PClassActor *parent = ammo->GetParentAmmo ();
-		AInventory *holdingammo = player->mo->FindInventory (parent);
-
+		auto ac = PClass::FindActor(NAME_Ammo);
+		auto parent = item->GetClass();
+		while (parent->ParentClass != ac) parent = (PClassActor*)(parent->ParentClass);
+		AInventory *holdingammo = player->mo->FindInventory(parent);
 		if (holdingammo != NULL && holdingammo->Amount >= holdingammo->MaxAmount)
 		{
 			return;
diff --git a/src/d_dehacked.cpp b/src/d_dehacked.cpp
index 1239d71bb..a30076642 100644
--- a/src/d_dehacked.cpp
+++ b/src/d_dehacked.cpp
@@ -75,7 +75,6 @@
 #include "v_text.h"
 #include "vmbuilder.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 
 // [SO] Just the way Randy said to do it :)
 // [RH] Made this CVAR_SERVERINFO
@@ -1536,7 +1535,7 @@ static int PatchSprite (int sprNum)
 static int PatchAmmo (int ammoNum)
 {
 	PClassActor *ammoType = NULL;
-	AAmmo *defaultAmmo = NULL;
+	AInventory *defaultAmmo = NULL;
 	int result;
 	int oldclip;
 	int dummy;
@@ -1549,7 +1548,7 @@ static int PatchAmmo (int ammoNum)
 		ammoType = AmmoNames[ammoNum];
 		if (ammoType != NULL)
 		{
-			defaultAmmo = (AAmmo *)GetDefaultByType (ammoType);
+			defaultAmmo = (AInventory*)GetDefaultByType (ammoType);
 			if (defaultAmmo != NULL)
 			{
 				max = &defaultAmmo->MaxAmount;
@@ -1575,8 +1574,8 @@ static int PatchAmmo (int ammoNum)
 	// Calculate the new backpack-given amounts for this ammo.
 	if (ammoType != NULL)
 	{
-		defaultAmmo->BackpackMaxAmount = defaultAmmo->MaxAmount * 2;
-		defaultAmmo->BackpackAmount = defaultAmmo->Amount;
+		defaultAmmo->IntVar("BackpackMaxAmount") = defaultAmmo->MaxAmount * 2;
+		defaultAmmo->IntVar("BackpackAmount") = defaultAmmo->Amount;
 	}
 
 	// Fix per-ammo/max-ammo amounts for descendants of the base ammo class
@@ -1591,7 +1590,7 @@ static int PatchAmmo (int ammoNum)
 
 			if (type->IsDescendantOf (ammoType))
 			{
-				defaultAmmo = (AAmmo *)GetDefaultByType (type);
+				defaultAmmo = (AInventory *)GetDefaultByType (type);
 				defaultAmmo->MaxAmount = *max;
 				defaultAmmo->Amount = Scale (defaultAmmo->Amount, *per, oldclip);
 			}
@@ -1673,7 +1672,7 @@ static int PatchWeapon (int weapNum)
 				info->AmmoType1 = (PClassInventory*)AmmoNames[val];
 				if (info->AmmoType1 != NULL)
 				{
-					info->AmmoGive1 = ((AAmmo*)GetDefaultByType (info->AmmoType1))->Amount * 2;
+					info->AmmoGive1 = ((AInventory*)GetDefaultByType (info->AmmoType1))->Amount * 2;
 					if (info->AmmoUse1 == 0)
 					{
 						info->AmmoUse1 = 1;
@@ -2930,7 +2929,7 @@ static bool LoadDehSupp ()
 					else
 					{
 						auto cls = PClass::FindActor(sc.String);
-						if (cls == NULL || !cls->IsDescendantOf(RUNTIME_CLASS(AAmmo)))
+						if (cls == NULL || !cls->IsDescendantOf(PClass::FindActor(NAME_Ammo)))
 						{
 							sc.ScriptError("Unknown ammo type '%s'", sc.String);
 						}
diff --git a/src/fragglescript/t_func.cpp b/src/fragglescript/t_func.cpp
index 7c5adb6bc..d3746a49e 100644
--- a/src/fragglescript/t_func.cpp
+++ b/src/fragglescript/t_func.cpp
@@ -69,7 +69,6 @@
 #include "p_setup.h"
 #include "p_spec.h"
 #include "r_utility.h"
-#include "a_ammo.h"
 #include "math/cmath.h"
 #include "g_levellocals.h"
 
@@ -2478,14 +2477,7 @@ static void FS_TakeInventory (AActor *actor, const char * type, int amount)
 			// If it's not ammo, destroy it. Ammo needs to stick around, even
 			// when it's zero for the benefit of the weapons that use it and 
 			// to maintain the maximum ammo amounts a backpack might have given.
-			if (item->GetClass()->ParentClass != RUNTIME_CLASS(AAmmo))
-			{
-				item->Destroy ();
-			}
-			else
-			{
-				item->Amount = 0;
-			}
+			item->DepleteOrDestroy();
 		}
 	}
 }
@@ -2628,7 +2620,7 @@ void FParser::SF_MaxPlayerAmmo()
 			if(amount < 0) amount = 0;
 			if (!iammo) 
 			{
-				iammo = static_cast<AAmmo *>(Spawn (ammotype));
+				iammo = static_cast<AInventory *>(Spawn (ammotype));
 				iammo->Amount = 0;
 				iammo->AttachToOwner (players[playernum].mo);
 			}
@@ -2644,13 +2636,13 @@ void FParser::SF_MaxPlayerAmmo()
 					break;
 				}
 			}
-			((AAmmo*)iammo)->BackpackMaxAmount=amount;
+			iammo->IntVar("BackpackMaxAmount") = amount;
 		}
 
 		t_return.type = svt_int;
 		AInventory * iammo = players[playernum].mo->FindInventory(ammotype);
 		if (iammo) t_return.value.i = iammo->MaxAmount;
-		else t_return.value.i = ((AAmmo*)GetDefaultByType(ammotype))->MaxAmount;
+		else t_return.value.i = ((AInventory*)GetDefaultByType(ammotype))->MaxAmount;
 	}
 }
 
diff --git a/src/g_inventory/a_ammo.cpp b/src/g_inventory/a_ammo.cpp
deleted file mode 100644
index b1765e1e4..000000000
--- a/src/g_inventory/a_ammo.cpp
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
-** a_ammo.cpp
-** Implements ammo and backpack items.
-**
-**---------------------------------------------------------------------------
-** Copyright 2000-2016 Randy Heit
-** Copyright 2006-2016 Cheistoph Oelckers
-** All rights reserved.
-**
-** Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions
-** are met:
-**
-** 1. Redistributions of source code must retain the above copyright
-**    notice, this list of conditions and the following disclaimer.
-** 2. Redistributions in binary form must reproduce the above copyright
-**    notice, this list of conditions and the following disclaimer in the
-**    documentation and/or other materials provided with the distribution.
-** 3. The name of the author may not be used to endorse or promote products
-**    derived from this software without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**---------------------------------------------------------------------------
-**
-*/
-
-#include "c_dispatch.h"
-#include "d_player.h"
-#include "serializer.h"
-
-IMPLEMENT_CLASS(AAmmo, false, false)
-
-DEFINE_FIELD(AAmmo, BackpackAmount)
-DEFINE_FIELD(AAmmo, BackpackMaxAmount)
-
-//===========================================================================
-//
-// AAmmo :: Serialize
-//
-//===========================================================================
-
-void AAmmo::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	auto def = (AAmmo*)GetDefault();
-	arc("backpackamount", BackpackAmount, def->BackpackAmount)
-		("backpackmaxamount", BackpackMaxAmount, def->BackpackMaxAmount);
-}
-
-//===========================================================================
-//
-// AAmmo :: GetParentAmmo
-//
-// Returns the least-derived ammo type that this ammo is a descendant of.
-// That is, if this ammo is an immediate subclass of Ammo, then this ammo's
-// type is returned. If this ammo's superclass is not Ammo, then this
-// function travels up the inheritance chain until it finds a type that is
-// an immediate subclass of Ammo and returns that.
-//
-// The intent of this is that all unique ammo types will be immediate
-// subclasses of Ammo. To make different pickups with different ammo amounts,
-// you subclass the type of ammo you want a different amount for and edit
-// that.
-//
-//===========================================================================
-
-PClassActor *AAmmo::GetParentAmmo () const
-{
-	PClass *type = GetClass();
-
-	while (type->ParentClass != RUNTIME_CLASS(AAmmo) && type->ParentClass != NULL)
-	{
-		type = type->ParentClass;
-	}
-	return static_cast<PClassActor *>(type);
-}
-
-DEFINE_ACTION_FUNCTION(AAmmo, GetParentAmmo)
-{
-	PARAM_SELF_PROLOGUE(AAmmo);
-	ACTION_RETURN_OBJECT(self->GetParentAmmo());
-}
diff --git a/src/g_inventory/a_ammo.h b/src/g_inventory/a_ammo.h
deleted file mode 100644
index 445f44a34..000000000
--- a/src/g_inventory/a_ammo.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma once
-#include "a_pickups.h"
-
-class AAmmo : public AInventory
-{
-	DECLARE_CLASS (AAmmo, AInventory)
-public:
-	
-	virtual void Serialize(FSerializer &arc) override;
-	PClassActor *GetParentAmmo () const;
-
-	int BackpackAmount, BackpackMaxAmount, DropAmount;
-};
-
diff --git a/src/g_inventory/a_pickups.cpp b/src/g_inventory/a_pickups.cpp
index b19fcf1f2..d5fa58a0b 100644
--- a/src/g_inventory/a_pickups.cpp
+++ b/src/g_inventory/a_pickups.cpp
@@ -20,7 +20,6 @@
 #include "p_spec.h"
 #include "serializer.h"
 #include "virtual.h"
-#include "a_ammo.h"
 #include "c_functions.h"
 #include "g_levellocals.h"
 
@@ -1314,29 +1313,7 @@ bool AInventory::TryPickup (AActor *&toucher)
 		ItemFlags &= ~IF_PICKUPGOOD;
 		GoAwayAndDie ();
 	}
-	else if (MaxAmount == 0 && !IsKindOf(RUNTIME_CLASS(AAmmo)))
-	{
-		// Special case: If an item's MaxAmount is 0, you can still pick it
-		// up if it is autoactivate-able.
-		if (!(ItemFlags & IF_AUTOACTIVATE))
-		{
-			return false;
-		}
-		// The item is placed in the inventory just long enough to be used.
-		toucher->AddInventory (this);
-		bool usegood = CallUse (true);
-		toucher->RemoveInventory (this);
-
-		if (usegood)
-		{
-			GoAwayAndDie ();
-		}
-		else
-		{
-			return false;
-		}
-	}
-	else
+	else if (MaxAmount > 0)
 	{
 		// Add the item to the inventory. It is not already there, or HandlePickup
 		// would have already taken care of it.
@@ -1374,6 +1351,25 @@ bool AInventory::TryPickup (AActor *&toucher)
 			}
 		}
 	}
+	else if (ItemFlags & IF_AUTOACTIVATE)
+	{
+		// Special case: If an item's MaxAmount is 0, you can still pick it
+		// up if it is autoactivate-able.
+
+		// The item is placed in the inventory just long enough to be used.
+		toucher->AddInventory(this);
+		bool usegood = CallUse(true);
+		toucher->RemoveInventory(this);
+
+		if (usegood)
+		{
+			GoAwayAndDie();
+		}
+		else
+		{
+			return false;
+		}
+	}
 	return true;
 }
 
diff --git a/src/g_inventory/a_weapons.cpp b/src/g_inventory/a_weapons.cpp
index 242181ced..1b7745979 100644
--- a/src/g_inventory/a_weapons.cpp
+++ b/src/g_inventory/a_weapons.cpp
@@ -54,7 +54,7 @@
 #include "serializer.h"
 #include "thingdef.h"
 #include "virtual.h"
-#include "a_ammo.h"
+
 
 #define BONUSADD 6
 
@@ -499,9 +499,9 @@ void AWeapon::AttachToOwner (AActor *other)
 //
 //===========================================================================
 
-AAmmo *AWeapon::AddAmmo (AActor *other, PClassActor *ammotype, int amount)
+AInventory *AWeapon::AddAmmo (AActor *other, PClassActor *ammotype, int amount)
 {
-	AAmmo *ammo;
+	AInventory *ammo;
 
 	if (ammotype == NULL)
 	{
@@ -518,10 +518,10 @@ AAmmo *AWeapon::AddAmmo (AActor *other, PClassActor *ammotype, int amount)
 	{
 		amount = int(amount * G_SkillProperty(SKILLP_AmmoFactor));
 	}
-	ammo = static_cast<AAmmo *>(other->FindInventory (ammotype));
+	ammo = other->FindInventory (ammotype);
 	if (ammo == NULL)
 	{
-		ammo = static_cast<AAmmo *>(Spawn (ammotype));
+		ammo = static_cast<AInventory *>(Spawn (ammotype));
 		ammo->Amount = MIN (amount, ammo->MaxAmount);
 		ammo->AttachToOwner (other);
 	}
@@ -545,7 +545,7 @@ AAmmo *AWeapon::AddAmmo (AActor *other, PClassActor *ammotype, int amount)
 //===========================================================================
 EXTERN_CVAR(Bool, sv_unlimited_pickup)
 
-bool AWeapon::AddExistingAmmo (AAmmo *ammo, int amount)
+bool AWeapon::AddExistingAmmo (AInventory *ammo, int amount)
 {
 	if (ammo != NULL && (ammo->Amount < ammo->MaxAmount || sv_unlimited_pickup))
 	{
diff --git a/src/g_inventory/a_weapons.h b/src/g_inventory/a_weapons.h
index 55354c139..ed18df421 100644
--- a/src/g_inventory/a_weapons.h
+++ b/src/g_inventory/a_weapons.h
@@ -1,7 +1,6 @@
 #pragma once
 
-#include "a_ammo.h"
-
+#include "a_pickups.h"
 class PClassWeapon;
 class AWeapon;
 
@@ -126,7 +125,7 @@ public:
 	float BobRangeX, BobRangeY;				// [XA] Bobbing range. Defines how far a weapon bobs in either direction.
 
 	// In-inventory instance variables
-	TObjPtr<AAmmo> Ammo1, Ammo2;
+	TObjPtr<AInventory> Ammo1, Ammo2;
 	TObjPtr<AWeapon> SisterWeapon;
 	float FOVScale;
 	int Crosshair;							// 0 to use player's crosshair
@@ -182,8 +181,8 @@ public:
 	};
 
 protected:
-	AAmmo *AddAmmo (AActor *other, PClassActor *ammotype, int amount);
-	bool AddExistingAmmo (AAmmo *ammo, int amount);
+	AInventory *AddAmmo (AActor *other, PClassActor *ammotype, int amount);
+	bool AddExistingAmmo (AInventory *ammo, int amount);
 	AWeapon *AddWeapon (PClassWeapon *weapon);
 };
 
diff --git a/src/g_shared/sbar.h b/src/g_shared/sbar.h
index d681eebad..414d2a730 100644
--- a/src/g_shared/sbar.h
+++ b/src/g_shared/sbar.h
@@ -294,7 +294,6 @@ int FindMugShotStateIndex(FName state);
 // Base Status Bar ----------------------------------------------------------
 
 class FTexture;
-class AAmmo;
 
 enum
 {
@@ -395,7 +394,7 @@ protected:
 
 	void RefreshBackground () const;
 
-	void GetCurrentAmmo (AAmmo *&ammo1, AAmmo *&ammo2, int &ammocount1, int &ammocount2) const;
+	void GetCurrentAmmo (AInventory *&ammo1, AInventory *&ammo2, int &ammocount1, int &ammocount2) const;
 
 public:
 	AInventory *ValidateInvFirst (int numVisible) const;
diff --git a/src/g_shared/sbarinfo.cpp b/src/g_shared/sbarinfo.cpp
index 5ba0b62b8..ca94ebc84 100644
--- a/src/g_shared/sbarinfo.cpp
+++ b/src/g_shared/sbarinfo.cpp
@@ -58,7 +58,6 @@
 #include "gstrings.h"
 #include "version.h"
 #include "cmdlib.h"
-#include "a_ammo.h"
 #include "g_levellocals.h"
 
 #define ARTIFLASH_OFFSET (statusBar->invBarOffset+6)
@@ -1517,7 +1516,7 @@ public:
 		return translationtables[TRANSLATION_Players][int(CPlayer - players)];
 	}
 
-	AAmmo *ammo1, *ammo2;
+	AInventory *ammo1, *ammo2;
 	int ammocount1, ammocount2;
 	ABasicArmor *armor;
 	FImageCollection Images;
diff --git a/src/g_shared/sbarinfo_commands.cpp b/src/g_shared/sbarinfo_commands.cpp
index 4cb587bc9..ccc7d8cc3 100644
--- a/src/g_shared/sbarinfo_commands.cpp
+++ b/src/g_shared/sbarinfo_commands.cpp
@@ -244,31 +244,31 @@ class CommandDrawImage : public SBarInfoCommandFlowControl
 				texture = TexMan(statusBar->CPlayer->mo->ScoreIcon);
 			else if(type == AMMO1)
 			{
-				AAmmo *ammo = statusBar->ammo1;
+				auto ammo = statusBar->ammo1;
 				if(ammo != NULL)
 					GetIcon(ammo);
 			}
 			else if(type == AMMO2)
 			{
-				AAmmo *ammo = statusBar->ammo2;
+				auto ammo = statusBar->ammo2;
 				if(ammo != NULL)
 					GetIcon(ammo);
 			}
 			else if(type == ARMOR)
 			{
-				ABasicArmor *armor = statusBar->armor;
+				auto armor = statusBar->armor;
 				if(armor != NULL && armor->Amount != 0)
 					GetIcon(armor);
 			}
 			else if(type == WEAPONICON)
 			{
-				AWeapon *weapon = statusBar->CPlayer->ReadyWeapon;
+				auto weapon = statusBar->CPlayer->ReadyWeapon;
 				if(weapon != NULL)
 					GetIcon(weapon);
 			}
 			else if(type == SIGIL)
 			{
-				AInventory *item = statusBar->CPlayer->mo->FindInventory(PClass::FindActor(NAME_Sigil));
+				auto item = statusBar->CPlayer->mo->FindInventory(PClass::FindActor(NAME_Sigil));
 				if (item != NULL)
 					texture = TexMan(item->Icon);
 			}
@@ -1076,10 +1076,10 @@ class CommandDrawNumber : public CommandDrawString
 						if(!parenthesized || !sc.CheckToken(TK_StringConst))
 							sc.MustGetToken(TK_Identifier);
 						inventoryItem = PClass::FindActor(sc.String);
-						if(inventoryItem == NULL || !RUNTIME_CLASS(AAmmo)->IsAncestorOf(inventoryItem)) //must be a kind of ammo
+						if(inventoryItem == NULL || !PClass::FindActor(NAME_Ammo)->IsAncestorOf(inventoryItem)) //must be a kind of ammo
 						{
 							sc.ScriptMessage("'%s' is not a type of ammo.", sc.String);
-							inventoryItem = RUNTIME_CLASS(AAmmo);
+							inventoryItem = PClass::FindActor(NAME_Ammo);
 						}
 
 						if(parenthesized) sc.MustGetToken(')');
@@ -1092,10 +1092,10 @@ class CommandDrawNumber : public CommandDrawString
 						if(!parenthesized || !sc.CheckToken(TK_StringConst))
 							sc.MustGetToken(TK_Identifier);
 						inventoryItem = PClass::FindActor(sc.String);
-						if(inventoryItem == NULL || !RUNTIME_CLASS(AAmmo)->IsAncestorOf(inventoryItem)) //must be a kind of ammo
+						if(inventoryItem == NULL || !PClass::FindActor(NAME_Ammo)->IsAncestorOf(inventoryItem)) //must be a kind of ammo
 						{
 							sc.ScriptMessage("'%s' is not a type of ammo.", sc.String);
-							inventoryItem = RUNTIME_CLASS(AAmmo);
+							inventoryItem = PClass::FindActor(NAME_Ammo);
 						}
 
 						if(parenthesized) sc.MustGetToken(')');
@@ -1435,7 +1435,7 @@ class CommandDrawNumber : public CommandDrawString
 				{
 					// num = statusBar.CPlayer.mo.GetEffectTicsForItem(inventoryItem) / TICRATE + 1;
 					static VMFunction *func = nullptr;
-					if (func == nullptr) func = static_cast<PFunction*>(RUNTIME_CLASS(APlayerPawn)->Symbols.FindSymbol("GetEffectTicsForItem", false))->Variants[0].Implementation;
+					if (func == nullptr) func = PClass::FindFunction(NAME_PlayerPawn, "GetEffectTicsForItem");
 					VMValue params[] = { statusBar->CPlayer->mo, inventoryItem };
 					int retv;
 					VMReturn ret(&retv);
@@ -2630,10 +2630,10 @@ class CommandDrawBar : public SBarInfoCommand
 						sc.MustGetToken(TK_Identifier);
 				type = AMMO;
 				data.inventoryItem = PClass::FindActor(sc.String);
-				if(data.inventoryItem == NULL || !RUNTIME_CLASS(AAmmo)->IsAncestorOf(data.inventoryItem)) //must be a kind of ammo
+				if(data.inventoryItem == NULL || !PClass::FindActor(NAME_Ammo)->IsAncestorOf(data.inventoryItem)) //must be a kind of ammo
 				{
 					sc.ScriptMessage("'%s' is not a type of ammo.", sc.String);
-					data.inventoryItem = RUNTIME_CLASS(AAmmo);
+					data.inventoryItem = PClass::FindActor(NAME_Ammo);
 				}
 
 				if(parenthesized) sc.MustGetToken(')');
@@ -2825,8 +2825,10 @@ class CommandDrawBar : public SBarInfoCommand
 					break;
 				case POWERUPTIME:
 				{
+					// [value, max] = statusBar.CPlayer.mo.GetEffectTicsForItem(inventoryItem);
+					// value++; max++;
 					static VMFunction *func = nullptr;
-					if (func == nullptr) func = static_cast<PFunction*>(RUNTIME_CLASS(APlayerPawn)->Symbols.FindSymbol("GetEffectTicsForItem", false))->Variants[0].Implementation;
+					if (func == nullptr) func = PClass::FindFunction(NAME_PlayerPawn, "GetEffectTicsForItem");
 					VMValue params[] = { statusBar->CPlayer->mo, data.inventoryItem };
 					VMReturn ret[2];
 					int ival;
@@ -3312,10 +3314,10 @@ class CommandWeaponAmmo : public SBarInfoNegatableFlowControl
 			for(int i = 0;i < 2;i++)
 			{
 				ammo[i] = PClass::FindClass(sc.String);
-				if(ammo[i] == NULL || !RUNTIME_CLASS(AAmmo)->IsAncestorOf(ammo[i])) //must be a kind of ammo
+				if(ammo[i] == NULL || !PClass::FindActor(NAME_Ammo)->IsAncestorOf(ammo[i])) //must be a kind of ammo
 				{
 					sc.ScriptMessage("'%s' is not a type of ammo.", sc.String);
-					ammo[i] = RUNTIME_CLASS(AAmmo);
+					ammo[i] = PClass::FindActor(NAME_Ammo);
 				}
 		
 				if(sc.CheckToken(TK_OrOr))
diff --git a/src/g_shared/shared_hud.cpp b/src/g_shared/shared_hud.cpp
index 839582d34..981b72779 100644
--- a/src/g_shared/shared_hud.cpp
+++ b/src/g_shared/shared_hud.cpp
@@ -44,7 +44,6 @@
 #include "w_wad.h"
 #include "a_keys.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "sbar.h"
 #include "sc_man.h"
 #include "templates.h"
@@ -527,7 +526,7 @@ static void AddAmmoToList(AWeapon * weapdef)
 		PClassInventory * ti = i==0? weapdef->AmmoType1 : weapdef->AmmoType2;
 		if (ti)
 		{
-			AAmmo * ammodef=(AAmmo*)GetDefaultByType(ti);
+			auto ammodef=(AInventory*)GetDefaultByType(ti);
 
 			if (ammodef && !(ammodef->ItemFlags&IF_INVBAR))
 			{
@@ -561,9 +560,9 @@ static void GetAmmoTextLengths(player_t *CPlayer, int& ammocur, int& ammomax)
 {
 	for (auto type : orderedammos)
 	{
-		AAmmo * ammoitem = static_cast<AAmmo*>(CPlayer->mo->FindInventory(type));
-		AAmmo * inv = nullptr == ammoitem
-			? static_cast<AAmmo*>(GetDefaultByType(type))
+		auto ammoitem = CPlayer->mo->FindInventory(type);
+		auto inv = nullptr == ammoitem
+			? static_cast<AInventory*>(GetDefaultByType(type))
 			: ammoitem;
 		assert(nullptr != inv);
 
@@ -648,9 +647,9 @@ static int DrawAmmo(player_t *CPlayer, int x, int y)
 	{
 
 		PClassInventory * type = orderedammos[i];
-		AAmmo * ammoitem = (AAmmo*)CPlayer->mo->FindInventory(type);
+		auto ammoitem = CPlayer->mo->FindInventory(type);
 
-		AAmmo * inv = ammoitem? ammoitem : (AAmmo*)GetDefaultByType(orderedammos[i]);
+		auto inv = ammoitem? ammoitem : (AInventory*)GetDefaultByType(orderedammos[i]);
 		FTextureID AltIcon = GetHUDIcon(type);
 		FTextureID icon = !AltIcon.isNull()? AltIcon : inv->Icon;
 		if (!icon.isValid()) continue;
diff --git a/src/g_shared/shared_sbar.cpp b/src/g_shared/shared_sbar.cpp
index 6a790f845..f8ed4a94b 100644
--- a/src/g_shared/shared_sbar.cpp
+++ b/src/g_shared/shared_sbar.cpp
@@ -1794,7 +1794,7 @@ AInventory *DBaseStatusBar::ValidateInvFirst (int numVisible) const
 //
 //============================================================================
 
-void DBaseStatusBar::GetCurrentAmmo (AAmmo *&ammo1, AAmmo *&ammo2, int &ammocount1, int &ammocount2) const
+void DBaseStatusBar::GetCurrentAmmo (AInventory *&ammo1, AInventory *&ammo2, int &ammocount1, int &ammocount2) const
 {
 	if (CPlayer->ReadyWeapon != NULL)
 	{
diff --git a/src/g_strife/strife_sbar.cpp b/src/g_strife/strife_sbar.cpp
index 1a8e216fd..5fc4a3ae6 100644
--- a/src/g_strife/strife_sbar.cpp
+++ b/src/g_strife/strife_sbar.cpp
@@ -13,7 +13,6 @@
 #include "templates.h"
 #include "a_keys.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "gi.h"
 #include "g_level.h"
 #include "colormatcher.h"
@@ -417,7 +416,7 @@ private:
 		}
 
 		// Ammo
-		AAmmo *ammo1, *ammo2;
+		AInventory *ammo1, *ammo2;
 		int ammocount1, ammocount2;
 
 		GetCurrentAmmo (ammo1, ammo2, ammocount1, ammocount2);
@@ -485,7 +484,7 @@ private:
 		}
 
 		// Draw ammo
-		AAmmo *ammo1, *ammo2;
+		AInventory *ammo1, *ammo2;
 		int ammocount1, ammocount2;
 
 		GetCurrentAmmo (ammo1, ammo2, ammocount1, ammocount2);
diff --git a/src/m_cheat.cpp b/src/m_cheat.cpp
index d68839359..94e0bde5e 100644
--- a/src/m_cheat.cpp
+++ b/src/m_cheat.cpp
@@ -48,7 +48,6 @@
 #include "r_utility.h"
 #include "a_morph.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "g_levellocals.h"
 #include "virtual.h"
 
diff --git a/src/namedef.h b/src/namedef.h
index 0a3af96cb..0122dbaad 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -716,6 +716,7 @@ xx(BlendColor)
 xx(Strength)
 xx(Mode)
 xx(PowerupType)
+xx(PlayerPawn)
 
 // Decorate compatibility functions
 xx(BuiltinTypeCheck)
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 8914ab788..5ebb0f640 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -84,7 +84,6 @@
 #include "thingdef.h"
 #include "a_pickups.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "r_data/colormaps.h"
 #include "g_levellocals.h"
 #include "stats.h"
@@ -8700,7 +8699,7 @@ scriptwait:
 				PClass *type = PClass::FindClass (FBehavior::StaticLookupString (STACK(1)));
 				AInventory *item;
 
-				if (type != NULL && type->ParentClass == RUNTIME_CLASS(AAmmo))
+				if (type != NULL && type->ParentClass == PClass::FindActor(NAME_Ammo))
 				{
 					item = activator->FindInventory (static_cast<PClassActor *>(type));
 					if (item != NULL)
@@ -8729,7 +8728,7 @@ scriptwait:
 				PClassActor *type = PClass::FindActor (FBehavior::StaticLookupString (STACK(2)));
 				AInventory *item;
 
-				if (type != NULL && type->ParentClass == RUNTIME_CLASS(AAmmo))
+				if (type != NULL && type->ParentClass == PClass::FindActor(NAME_Ammo))
 				{
 					item = activator->FindInventory (type);
 					if (item != NULL)
diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index 83b96af39..e4a902b44 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -51,7 +51,6 @@
 #include "p_spec.h"
 #include "p_checkposition.h"
 #include "math/cmath.h"
-#include "a_ammo.h"
 #include "g_levellocals.h"
 
 #include "gi.h"
@@ -3228,7 +3227,7 @@ void ModifyDropAmount(AInventory *inv, int dropamount)
 
 	if (dropamount > 0)
 	{
-		if (flagmask != 0 && inv->IsKindOf(RUNTIME_CLASS(AAmmo)))
+		if (flagmask != 0 && inv->IsKindOf(PClass::FindActor(NAME_Ammo)))
 		{
 			inv->Amount = int(dropamount * dropammofactor);
 			inv->ItemFlags |= IF_IGNORESKILL;
@@ -3238,10 +3237,10 @@ void ModifyDropAmount(AInventory *inv, int dropamount)
 			inv->Amount = dropamount;
 		}
 	}
-	else if (inv->IsKindOf (RUNTIME_CLASS(AAmmo)))
+	else if (inv->IsKindOf (PClass::FindActor(NAME_Ammo)))
 	{
 		// Half ammo when dropped by bad guys.
-		int amount = static_cast<AAmmo *>(inv)->DropAmount;
+		int amount = inv->IntVar("DropAmount");
 		if (amount <= 0)
 		{
 			amount = MAX(1, int(inv->Amount * dropammofactor));
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 4bf890462..045679b83 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -70,7 +70,6 @@
 #include "d_player.h"
 #include "virtual.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "g_levellocals.h"
 #include "a_morph.h"
 
@@ -906,7 +905,7 @@ bool AActor::TakeInventory(PClassActor *itemclass, int amount, bool fromdecorate
 	// and infinite ammo is on
 	if (notakeinfinite &&
 	((dmflags & DF_INFINITE_AMMO) || (player && player->cheats & CF_INFINITEAMMO)) &&
-		item->IsKindOf(RUNTIME_CLASS(AAmmo)))
+		item->IsKindOf(PClass::FindActor(NAME_Ammo)))
 	{
 		// Nothing to do here, except maybe res = false;? Would it make sense?
 		result = false;
@@ -1171,7 +1170,7 @@ bool AActor::GiveAmmo (PClassInventory *type, int amount)
 DEFINE_ACTION_FUNCTION(AActor, GiveAmmo)
 {
 	PARAM_SELF_PROLOGUE(AActor);
-	PARAM_CLASS(type, AAmmo);
+	PARAM_CLASS(type, AInventory);
 	PARAM_INT(amount);
 	ACTION_RETURN_BOOL(self->GiveAmmo(type, amount));
 }
diff --git a/src/p_user.cpp b/src/p_user.cpp
index b04a7be01..deb6fbb22 100644
--- a/src/p_user.cpp
+++ b/src/p_user.cpp
@@ -60,7 +60,6 @@
 #include "p_spec.h"
 #include "virtual.h"
 #include "a_armor.h"
-#include "a_ammo.h"
 #include "g_levellocals.h"
 
 static FRandom pr_skullpop ("SkullPop");
@@ -1171,7 +1170,7 @@ void APlayerPawn::FilterCoopRespawnInventory (APlayerPawn *oldplayer)
 				item->Destroy();
 			}
 			else if ((dmflags & (DF_COOP_LOSE_AMMO | DF_COOP_HALVE_AMMO)) &&
-				item->IsKindOf(RUNTIME_CLASS(AAmmo)))
+				item->IsKindOf(PClass::FindActor(NAME_Ammo)))
 			{
 				if (defitem == NULL)
 				{
diff --git a/src/scripting/thingdef_properties.cpp b/src/scripting/thingdef_properties.cpp
index 3eed959f3..eaad49e9c 100644
--- a/src/scripting/thingdef_properties.cpp
+++ b/src/scripting/thingdef_properties.cpp
@@ -69,7 +69,6 @@
 #include "r_data/colormaps.h"
 #include "a_weaponpiece.h"
 #include "vmbuilder.h"
-#include "a_ammo.h"
 #include "a_keys.h"
 #include "g_levellocals.h"
 
@@ -98,9 +97,9 @@ static PClassActor *FindClassTentative(const char *name, PClass *ancestor, bool
 	}
 	return static_cast<PClassActor *>(cls);
 }
-static AAmmo::MetaClass *FindClassTentativeAmmo(const char *name, bool optional = false)
+static AInventory::MetaClass *FindClassTentativeAmmo(const char *name, bool optional = false)
 {
-	return static_cast<AAmmo::MetaClass *>(FindClassTentative(name, RUNTIME_CLASS(AAmmo), optional));
+	return static_cast<PClassInventory *>(FindClassTentative(name, PClass::FindActor(NAME_Ammo), optional));
 }
 static AWeapon::MetaClass *FindClassTentativeWeapon(const char *name, bool optional = false)
 {
@@ -1742,33 +1741,6 @@ DEFINE_CLASS_PROPERTY(forbiddento, Ssssssssssssssssssss, Inventory)
 	}
 }
 
-//==========================================================================
-//
-//==========================================================================
-DEFINE_CLASS_PROPERTY(backpackamount, I, Ammo)
-{
-	PROP_INT_PARM(i, 0);
-	defaults->BackpackAmount = i;
-}
-
-//==========================================================================
-//
-//==========================================================================
-DEFINE_CLASS_PROPERTY(backpackmaxamount, I, Ammo)
-{
-	PROP_INT_PARM(i, 0);
-	defaults->BackpackMaxAmount = i;
-}
-
-//==========================================================================
-//
-//==========================================================================
-DEFINE_CLASS_PROPERTY(dropamount, I, Ammo)
-{
-	PROP_INT_PARM(i, 0);
-	defaults->DropAmount = i;
-}
-
 //==========================================================================
 //
 //==========================================================================
diff --git a/wadsrc/static/zscript/inventory/ammo.txt b/wadsrc/static/zscript/inventory/ammo.txt
index be9933a70..ba087a894 100644
--- a/wadsrc/static/zscript/inventory/ammo.txt
+++ b/wadsrc/static/zscript/inventory/ammo.txt
@@ -4,7 +4,7 @@
 **
 **---------------------------------------------------------------------------
 ** Copyright 2000-2016 Randy Heit
-** Copyright 2006-2017 Cheistoph Oelckers
+** Copyright 2006-2017 Christoph Oelckers
 ** All rights reserved.
 **
 ** Redistribution and use in source and binary forms, with or without
@@ -33,18 +33,49 @@
 **
 */
 
-class Ammo : Inventory native
+class Ammo : Inventory
 {
-	native int BackpackAmount;
-	native int BackpackMaxAmount;
+	int BackpackAmount;
+	int BackpackMaxAmount;
+	/*meta*/ int DropAmount;
 	
+	property BackpackAmount: BackpackAmount;
+	property BackpackMaxAmount: BackpackMaxAmount;
+	property DropAmount: DropAmount;
+
 	Default
 	{
 		+INVENTORY.KEEPDEPLETED
 		Inventory.PickupSound "misc/ammo_pkup";
 	}
 
-	native Class<Actor> GetParentAmmo ();
+	//===========================================================================
+	//
+	// AAmmo :: GetParentAmmo
+	//
+	// Returns the least-derived ammo type that this ammo is a descendant of.
+	// That is, if this ammo is an immediate subclass of Ammo, then this ammo's
+	// type is returned. If this ammo's superclass is not Ammo, then this
+	// function travels up the inheritance chain until it finds a type that is
+	// an immediate subclass of Ammo and returns that.
+	//
+	// The intent of this is that all unique ammo types will be immediate
+	// subclasses of Ammo. To make different pickups with different ammo amounts,
+	// you subclass the type of ammo you want a different amount for and edit
+	// that.
+	//
+	//===========================================================================
+
+	Class<Ammo> GetParentAmmo ()
+	{
+		class<Object> type = GetClass();
+
+		while (type.GetParentClass() != "Ammo" && type.GetParentClass() != NULL)
+		{
+			type = type.GetParentClass();
+		}
+		return (class<Ammo>)(type);
+	}
 
 	//===========================================================================
 	//
@@ -113,7 +144,7 @@ class Ammo : Inventory native
 		}
 
 		let type = GetParentAmmo();
-		if (GetClass() == type)
+		if (GetClass() != type && type != null)
 		{
 			if (!GoAway ())
 			{