diff --git a/data/json/EraOfDecay/ammo_effects.json b/data/json/EraOfDecay/ammo_effects.json
new file mode 100644
index 0000000000000..ba679f9709052
--- /dev/null
+++ b/data/json/EraOfDecay/ammo_effects.json
@@ -0,0 +1,7 @@
+[
+  {
+    "id": "AMMO_25MM_HEI",
+    "type": "ammo_effect",
+    "explosion": { "power": 54, "shrapnel": { "casing_mass": 153, "fragment_mass": 0.08 } }
+  }
+]
diff --git a/data/json/EraOfDecay/ammo_types.json b/data/json/EraOfDecay/ammo_types.json
index d96c0da694597..d6d3284c14365 100644
--- a/data/json/EraOfDecay/ammo_types.json
+++ b/data/json/EraOfDecay/ammo_types.json
@@ -4,5 +4,11 @@
     "id": "salt",
     "name": "salt",
     "default": "salt"
+  },
+  {
+    "type": "ammunition_type",
+    "id": "25mm",
+    "name": "25x137mm",
+    "default": "25mm_hei"
   }
 ]
diff --git a/data/json/EraOfDecay/itemgroups/guns.json b/data/json/EraOfDecay/itemgroups/guns.json
new file mode 100644
index 0000000000000..70a3fbb243f7f
--- /dev/null
+++ b/data/json/EraOfDecay/itemgroups/guns.json
@@ -0,0 +1,21 @@
+[
+  {
+    "type": "item_group",
+    "id": "guns_launcher_heavy",
+    "items": [
+      [ "25mm_apds", 10 ],
+      [ "25mm_apfsds", 10 ],
+      [ "25mm_hei", 5 ],
+      { "item": "belt25mm", "contents-group": "25mm_ammo", "prob": 10 }
+    ]
+  },
+  {
+    "type": "item_group",
+    "id": "25mm_ammo",
+    "items": [
+      { "item": "25mm_apds", "prob": 25, "charges": [ 1, 100 ] },
+      { "item": "25mm_apfsds", "prob": 25, "charges": [ 1, 100 ] },
+      { "item": "25mm_hei", "prob": 50, "charges": [ 1, 100 ] }
+    ]
+  }
+]
diff --git a/data/json/EraOfDecay/items/abstract.json b/data/json/EraOfDecay/items/abstract.json
index e86db0b96db09..c5359958e3cf7 100644
--- a/data/json/EraOfDecay/items/abstract.json
+++ b/data/json/EraOfDecay/items/abstract.json
@@ -75,5 +75,12 @@
     "name": { "str": "base large shield" },
     "longest_side": "120 cm",
     "techniques": [ "WBLOCK_3" ]
+  },
+  {
+    "abstract": "steel_casing",
+    "copy-from": "casing",
+    "type": "GENERIC",
+    "name": { "str": "steel casing from ammunition cartridge" },
+    "material": [ "steel" ]
   }
 ]
diff --git a/data/json/EraOfDecay/items/ammo/25mm.json b/data/json/EraOfDecay/items/ammo/25mm.json
new file mode 100644
index 0000000000000..09e8fc23873c7
--- /dev/null
+++ b/data/json/EraOfDecay/items/ammo/25mm.json
@@ -0,0 +1,93 @@
+[
+  {
+    "type": "AMMO",
+    "id": "25mm_apds",
+    "price": "49 USD",
+    "price_postapoc": "10 USD",
+    "name": { "str_sp": "25x137mm APDS-T" },
+    "symbol": "=",
+    "color": "yellow",
+    "description": "A 25x137mm M791 tracer round with an armor-piercing discarding sabot projectile with a tungsten alloy penetrator.  Used by autocannons primarily against light armored vehicles and slow-moving aerial targets.",
+    "material": [ "steel" ],
+    "volume": "2700 ml",
+    "weight": "458 g",
+    "longest_side": "223 mm",
+    "ammo_type": "25mm",
+    "casing": "25mm_casing",
+    "damage": { "damage_type": "bullet", "amount": 285, "armor_penetration": 102 },
+    "range": 60,
+    "dispersion": 125,
+    "recoil": 56250,
+    "count": 15,
+    "flags": [ "IRREPLACEABLE_CONSUMABLE" ],
+    "effects": [ "COOKOFF", "INCENDIARY" ]
+  },
+  {
+    "type": "AMMO",
+    "id": "25mm_apfsds",
+    "copy-from": "25mm_apds",
+    "price": "98 USD",
+    "price_postapoc": "15 USD",
+    "name": { "str_sp": "25x137mm APFSDS-T" },
+    "description": "A 25x137mm M919 tracer round with an armor-piercing fin-stabilized discarding sabot projectile with a depleted uranium penetrator.  Used by autocannons primarily against light armored vehicles and slow-moving aerial targets.",
+    "weight": "454 g",
+    "damage": { "damage_type": "bullet", "amount": 304, "armor_penetration": 163 }
+  },
+  {
+    "type": "AMMO",
+    "id": "25mm_hei",
+    "copy-from": "25mm_apds",
+    "price": "49 USD",
+    "price_postapoc": "10 USD",
+    "name": { "str_sp": "25x137mm HEI-T" },
+    "description": "A 25x137mm M792 tracer round with an high explosive incendiary projectile, which explodes on impact, scattering fragments.  Used by autocannons against unarmored vehicles and to suppress infantry.",
+    "weight": "501 g",
+    "damage": { "damage_type": "bullet", "amount": 285 },
+    "explode_in_fire": true,
+    "extend": { "effects": [ "AMMO_25MM_HEI" ] },
+    "delete": { "effects": [ "COOKOFF" ] }
+  },
+  {
+    "type": "AMMO",
+    "id": "25mm_slug_t",
+    "copy-from": "25mm_apds",
+    "name": { "str_sp": "25x137mm tracer slug, reloaded" },
+    "description": "A 25x137mm autocannon round with its primer replaced, and loaded with a machined steel projectile with a tracer compound.  Not as effective as the real thing, but still fairly potent.",
+    "weight": "501 g",
+    "proportional": { "price": 0.7, "damage": { "damage_type": "bullet", "amount": 0.9, "armor_penetration": 0.5 }, "dispersion": 1.1 },
+    "extend": { "effects": [ "RECYCLED" ] },
+    "delete": { "flags": [ "IRREPLACEABLE_CONSUMABLE" ] }
+  },
+  {
+    "type": "AMMO",
+    "id": "25mm_slug",
+    "copy-from": "25mm_slug_t",
+    "name": { "str_sp": "25x137mm slug, reloaded" },
+    "description": "A 25x137mm autocannon round with its primer replaced, and loaded with a machined steel projectile.  Not as effective as the real thing, but still fairly potent.",
+    "delete": { "effects": [ "INCENDIARY" ] }
+  },
+  {
+    "type": "AMMO",
+    "id": "bp_25mm_slug_t",
+    "copy-from": "25mm_apds",
+    "name": { "str_sp": "25x137mm tracer slug, black powder" },
+    "description": "A 25x137mm autocannon round with its primer replaced, and loaded with a machined steel projectile with a tracer compound.  Not as effective as the real thing, but still fairly potent.  Someone was down on their luck when they hand-reloaded this one - it's filled with black powder instead of smokeless powder.  Expect lower velocity, muzzle smoke, and a dirtier barrel if you shoot it.",
+    "weight": "501 g",
+    "proportional": {
+      "price": 0.3,
+      "damage": { "damage_type": "bullet", "amount": 0.76, "armor_penetration": 0.25 },
+      "recoil": 0.76,
+      "dispersion": 1.2
+    },
+    "extend": { "effects": [ "RECYCLED", "BLACKPOWDER", "MUZZLE_SMOKE" ] },
+    "delete": { "flags": [ "IRREPLACEABLE_CONSUMABLE" ] }
+  },
+  {
+    "type": "AMMO",
+    "id": "bp_25mm_slug",
+    "copy-from": "bp_25mm_slug_t",
+    "name": { "str_sp": "25x137mm slug, black powder" },
+    "description": "A 25x137mm autocannon round with its primer replaced, and loaded with a machined steel projectile.  Not as effective as the real thing, but still fairly potent.  Someone was down on their luck when they hand-reloaded this one - it's filled with black powder instead of smokeless powder.  Expect lower velocity, muzzle smoke, and a dirtier barrel if you shoot it.",
+    "delete": { "effects": [ "INCENDIARY" ] }
+  }
+]
diff --git a/data/json/EraOfDecay/items/books/launcher.json b/data/json/EraOfDecay/items/books/launcher.json
new file mode 100644
index 0000000000000..adf1ddfb4bef1
--- /dev/null
+++ b/data/json/EraOfDecay/items/books/launcher.json
@@ -0,0 +1,22 @@
+[
+  {
+    "type": "BOOK",
+    "id": "textbook_launcher",
+    "category": "manuals",
+    "name": { "str": "Artillery and Field Gunnery", "str_pl": "copies of Artillery and Field Gunnery" },
+    "max_level": 6,
+    "description": "A textbook on the history of modern artillery, with a number of illustrations and excerpts from various field manuals.  A competent handloader or mechanic might find additional uses for the more technical parts of the text.",
+    "weight": "1120 g",
+    "color": "green",
+    "intelligence": 8,
+    "symbol": "?",
+    "material": [ "paper" ],
+    "volume": "1 L",
+    "time": "30 m",
+    "fun": 0,
+    "skill": "launcher",
+    "price": "60 USD",
+    "price_postapoc": "25 USD",
+    "required_level": 3
+  }
+]
diff --git a/data/json/EraOfDecay/items/generic/ammolink.json b/data/json/EraOfDecay/items/generic/ammolink.json
index e201ccaca8323..fde0f2d223287 100644
--- a/data/json/EraOfDecay/items/generic/ammolink.json
+++ b/data/json/EraOfDecay/items/generic/ammolink.json
@@ -5,5 +5,16 @@
     "type": "GENERIC",
     "name": { "str": ".30-06 ammo belt linkage" },
     "use_action": { "type": "ammobelt", "belt": "belt3006" }
+  },
+  {
+    "id": "ammolink25mm",
+    "copy-from": "ammolink",
+    "type": "GENERIC",
+    "name": { "str": "25x137mm ammo belt linkage" },
+    "description": "An M28 steel linkage from a disintegrating 25x137mm ammo belt.",
+    "weight": "76 g",
+    "volume": "20 ml",
+    "longest_side": "3 cm",
+    "use_action": { "type": "ammobelt", "belt": "belt25mm" }
   }
 ]
diff --git a/data/json/EraOfDecay/items/generic/casing.json b/data/json/EraOfDecay/items/generic/casing.json
new file mode 100644
index 0000000000000..cfdc591913eb0
--- /dev/null
+++ b/data/json/EraOfDecay/items/generic/casing.json
@@ -0,0 +1,12 @@
+[
+  {
+    "type": "GENERIC",
+    "id": "25mm_casing",
+    "copy-from": "steel_casing",
+    "name": { "str": "25x137mm casing" },
+    "description": "An empty steel casing from a 25x137mm cartridge.",
+    "volume": "150 ml",
+    "weight": "80 g",
+    "longest_side": "137 mm"
+  }
+]
diff --git a/data/json/EraOfDecay/items/generic/parts.json b/data/json/EraOfDecay/items/generic/parts.json
index fdd4549eea3bb..d6da0217744a6 100644
--- a/data/json/EraOfDecay/items/generic/parts.json
+++ b/data/json/EraOfDecay/items/generic/parts.json
@@ -86,5 +86,23 @@
     "color": "brown",
     "symbol": ",",
     "material": [ "leather" ]
+  },
+  {
+    "type": "AMMO",
+    "id": "25mm_primer",
+    "category": "spare_parts",
+    "price": "50 USD",
+    "price_postapoc": "10 USD",
+    "name": { "str": "25x137mm primer" },
+    "symbol": "=",
+    "color": "dark_gray",
+    "description": "An M115 percussion primer from a 25x137mm round.",
+    "material": [ "steel", "powder" ],
+    "volume": "100 ml",
+    "weight": "5 g",
+    "longest_side": "6 mm",
+    "ammo_type": "components",
+    "count": 50,
+    "effects": [ "COOKOFF" ]
   }
 ]
diff --git a/data/json/EraOfDecay/items/guns/25mm.json b/data/json/EraOfDecay/items/guns/25mm.json
new file mode 100644
index 0000000000000..0c5ee416e8f01
--- /dev/null
+++ b/data/json/EraOfDecay/items/guns/25mm.json
@@ -0,0 +1,34 @@
+[
+  {
+    "id": "25mm_autocannon",
+    "looks_like": "cannon_3in_ordnance",
+    "type": "GUN",
+    "reload_noise_volume": 10,
+    "handling": 10,
+    "symbol": "(",
+    "color": "dark_gray",
+    "name": { "str": "M242 Bushmaster autocannon" },
+    "description": "An autocannon chambered in 25x137mm and driven by an electric motor, designed for the Bradley IFV and other ground vehicles, with some naval use as well.  It needs to be mounted on a vehicle to fire.",
+    "//": "Should have dual-feed capability (able to load two magazines at once and fire from either), but this isn't currently supported for vehicle-mounted weapons.  Gun is full-auto, but rate of fire is too slow to qualify for 2-round burst.",
+    "price": "28000 USD",
+    "price_postapoc": "75 USD",
+    "material": [ "qt_steel" ],
+    "flags": [ "VEHICLE_GUN_ONLY", "NEVER_JAMS", "USE_UPS" ],
+    "skill": "launcher",
+    "ammo": "25mm",
+    "weight": "110 kg",
+    "volume": "60 L",
+    "longest_side": "2743 mm",
+    "barrel_length": "2032 mm",
+    "melee_damage": { "bash": 30 },
+    "to_hit": -4,
+    "dispersion": 15,
+    "durability": 9,
+    "range": 110,
+    "modes": [ [ "DEFAULT", "auto", 1 ] ],
+    "min_veh_mass": "2500 kg",
+    "reload": 400,
+    "energy_drain": "1 kJ",
+    "pocket_data": [ { "pocket_type": "MAGAZINE_WELL", "item_restriction": [ "belt25mm" ] } ]
+  }
+]
diff --git a/data/json/EraOfDecay/items/magazines/25mm.json b/data/json/EraOfDecay/items/magazines/25mm.json
new file mode 100644
index 0000000000000..3117c45649abc
--- /dev/null
+++ b/data/json/EraOfDecay/items/magazines/25mm.json
@@ -0,0 +1,14 @@
+[
+  {
+    "id": "belt25mm",
+    "copy-from": "magazine_belt",
+    "type": "MAGAZINE",
+    "name": { "str": "25x137mm ammo belt" },
+    "description": "A disintegrating ammo belt consisting of M28 steel linkages holding 25x137mm cartidges together.",
+    "ammo_type": "25mm",
+    "default_ammo": "25mm_hei",
+    "capacity": 100,
+    "linkage": "ammolink25mm",
+    "pocket_data": [ { "pocket_type": "MAGAZINE", "rigid": true, "ammo_restriction": { "25mm": 100 } } ]
+  }
+]
diff --git a/data/json/EraOfDecay/recipes/ammo/components.json b/data/json/EraOfDecay/recipes/ammo/components.json
index ac7c04e537931..d6be7deb462db 100644
--- a/data/json/EraOfDecay/recipes/ammo/components.json
+++ b/data/json/EraOfDecay/recipes/ammo/components.json
@@ -68,5 +68,24 @@
       [ [ "chem_camphor", 40 ] ],
       [ [ "chem_nitroglycerin", 142 ] ]
     ]
+  },
+  {
+    "type": "recipe",
+    "activity_level": "LIGHT_EXERCISE",
+    "result": "25mm_primer",
+    "category": "CC_*",
+    "subcategory": "CSC_*_NESTED",
+    "skill_used": "fabrication",
+    "skills_required": [ "gun", 3 ],
+    "difficulty": 4,
+    "time": "45 m",
+    "book_learn": [ [ "textbook_launcher", 4 ] ],
+    "proficiencies": [ { "proficiency": "prof_intro_chemistry" } ],
+    "qualities": [ { "id": "HAMMER", "level": 3 } ],
+    "tools": [ [ [ "swage", -1 ] ] ],
+    "components": [
+      [ [ "can_drink", 2 ], [ "can_food", 2 ], [ "canister_empty", 2 ], [ "scrap", 4 ] ],
+      [ [ "chem_mercury_fulminate", 3 ] ]
+    ]
   }
 ]
diff --git a/data/json/EraOfDecay/recipes/ammo/other.json b/data/json/EraOfDecay/recipes/ammo/other.json
index 896ef1ba10381..fea0747d33138 100644
--- a/data/json/EraOfDecay/recipes/ammo/other.json
+++ b/data/json/EraOfDecay/recipes/ammo/other.json
@@ -47,5 +47,102 @@
       [ [ "chem_turpentine", 1 ] ]
     ],
     "flags": [ "BLIND_HARD", "NEVER_FAIL" ]
+  },
+  {
+    "result": "25mm_slug",
+    "type": "recipe",
+    "activity_level": "LIGHT_EXERCISE",
+    "category": "CC_AMMO",
+    "subcategory": "CSC_AMMO_OTHER",
+    "skill_used": "fabrication",
+    "difficulty": 6,
+    "time": "4 h",
+    "book_learn": [ [ "textbook_launcher", 5 ] ],
+    "proficiencies": [
+      { "proficiency": "prof_handloading" },
+      { "proficiency": "prof_carpentry_basic" },
+      { "proficiency": "prof_metalworking" },
+      { "proficiency": "prof_blacksmithing" },
+      { "proficiency": "prof_machining" },
+      { "proficiency": "prof_machining_skilled" }
+    ],
+    "charges": 1,
+    "using": [ [ "blacksmithing_standard", 1 ], [ "steel_tiny", 1 ] ],
+    "tools": [ [ [ "heavy_lathe_tool", 50 ] ], [ [ "hydraulic_press_tool", 50 ] ] ],
+    "components": [ [ [ "25mm_casing", 1 ] ], [ [ "gunpowder", 2200 ], [ "gunpowder_artillery", 2200 ] ], [ [ "25mm_primer", 1 ] ] ]
+  },
+  {
+    "result": "25mm_slug_t",
+    "type": "recipe",
+    "activity_level": "LIGHT_EXERCISE",
+    "category": "CC_AMMO",
+    "subcategory": "CSC_AMMO_OTHER",
+    "skill_used": "fabrication",
+    "difficulty": 6,
+    "time": "4 h",
+    "book_learn": [ [ "textbook_launcher", 5 ] ],
+    "proficiencies": [
+      { "proficiency": "prof_handloading" },
+      { "proficiency": "prof_carpentry_basic" },
+      { "proficiency": "prof_metalworking" },
+      { "proficiency": "prof_blacksmithing" },
+      { "proficiency": "prof_machining" },
+      { "proficiency": "prof_machining_skilled" }
+    ],
+    "charges": 1,
+    "using": [ [ "blacksmithing_standard", 1 ], [ "steel_tiny", 1 ] ],
+    "tools": [ [ [ "heavy_lathe_tool", 50 ] ], [ [ "hydraulic_press_tool", 50 ] ] ],
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "gunpowder", 2200 ], [ "gunpowder_artillery", 2200 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "incendiary", 20 ] ]
+    ]
+  },
+  {
+    "result": "bp_25mm_slug",
+    "type": "recipe",
+    "activity_level": "LIGHT_EXERCISE",
+    "category": "CC_AMMO",
+    "subcategory": "CSC_AMMO_OTHER",
+    "skill_used": "fabrication",
+    "difficulty": 6,
+    "time": "4 h",
+    "book_learn": [ [ "textbook_launcher", 5 ] ],
+    "proficiencies": [
+      { "proficiency": "prof_handloading" },
+      { "proficiency": "prof_carpentry_basic" },
+      { "proficiency": "prof_metalworking" },
+      { "proficiency": "prof_blacksmithing" },
+      { "proficiency": "prof_machining" },
+      { "proficiency": "prof_machining_skilled" }
+    ],
+    "charges": 1,
+    "using": [ [ "blacksmithing_standard", 1 ], [ "steel_tiny", 1 ] ],
+    "tools": [ [ [ "heavy_lathe_tool", 50 ] ], [ [ "hydraulic_press_tool", 50 ] ] ],
+    "components": [ [ [ "25mm_casing", 1 ] ], [ [ "chem_black_powder", 2200 ] ], [ [ "25mm_primer", 1 ] ] ]
+  },
+  {
+    "result": "bp_25mm_slug_t",
+    "type": "recipe",
+    "activity_level": "LIGHT_EXERCISE",
+    "category": "CC_AMMO",
+    "subcategory": "CSC_AMMO_OTHER",
+    "skill_used": "fabrication",
+    "difficulty": 6,
+    "time": "4 h",
+    "book_learn": [ [ "textbook_launcher", 5 ] ],
+    "proficiencies": [
+      { "proficiency": "prof_handloading" },
+      { "proficiency": "prof_carpentry_basic" },
+      { "proficiency": "prof_metalworking" },
+      { "proficiency": "prof_blacksmithing" },
+      { "proficiency": "prof_machining" },
+      { "proficiency": "prof_machining_skilled" }
+    ],
+    "charges": 1,
+    "using": [ [ "blacksmithing_standard", 1 ], [ "steel_tiny", 1 ] ],
+    "tools": [ [ [ "heavy_lathe_tool", 50 ] ], [ [ "hydraulic_press_tool", 50 ] ] ],
+    "components": [ [ [ "25mm_casing", 1 ] ], [ [ "chem_black_powder", 2200 ] ], [ [ "25mm_primer", 1 ] ], [ [ "incendiary", 20 ] ] ]
   }
 ]
diff --git a/data/json/EraOfDecay/recipes/recipe_disassembly.json b/data/json/EraOfDecay/recipes/recipe_disassembly.json
index 69ab3ca42d614..19af7bfc479bd 100644
--- a/data/json/EraOfDecay/recipes/recipe_disassembly.json
+++ b/data/json/EraOfDecay/recipes/recipe_disassembly.json
@@ -119,5 +119,121 @@
       [ [ "e_scrap", 16 ] ],
       [ [ "circuit", 8 ] ]
     ]
+  },
+  {
+    "result": "25mm_apds",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "CUT", "level": 1 }, { "id": "SAW_M", "level": 2 } ],
+    "//": "Could add tungsten alloy here once it has some use.",
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "gunpowder_artillery", 2200 ] ],
+      [ [ "incendiary", 20 ] ],
+      [ [ "scrap_aluminum", 1 ] ],
+      [ [ "plastic_chunk", 1 ] ]
+    ]
+  },
+  {
+    "result": "25mm_apfsds",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "CUT", "level": 1 }, { "id": "SAW_M", "level": 2 } ],
+    "//": "Could add depleted uranium here once it has some use.",
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "gunpowder_artillery", 2200 ] ],
+      [ [ "incendiary", 20 ] ],
+      [ [ "scrap_aluminum", 1 ] ],
+      [ [ "plastic_chunk", 1 ] ]
+    ]
+  },
+  {
+    "result": "25mm_hei",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 5,
+    "time": "10 m",
+    "qualities": [ { "id": "CUT", "level": 1 }, { "id": "SAW_M", "level": 2 } ],
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "gunpowder_artillery", 2200 ] ],
+      [ [ "incendiary", 20 ] ],
+      [ [ "chem_compositionb", 32 ] ],
+      [ [ "impact_fuze", 1 ] ],
+      [ [ "scrap", 3 ] ],
+      [ [ "scrap_aluminum", 1 ] ]
+    ]
+  },
+  {
+    "result": "25mm_slug",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "SAW_M", "level": 2 } ],
+    "components": [ [ [ "25mm_casing", 1 ] ], [ [ "25mm_primer", 1 ] ], [ [ "gunpowder", 2200 ] ], [ [ "scrap", 4 ] ] ]
+  },
+  {
+    "result": "25mm_slug_t",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "SAW_M", "level": 2 } ],
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "gunpowder", 2200 ] ],
+      [ [ "incendiary", 20 ] ],
+      [ [ "scrap", 4 ] ]
+    ]
+  },
+  {
+    "result": "bp_25mm_slug",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "SAW_M", "level": 2 } ],
+    "components": [ [ [ "25mm_casing", 1 ] ], [ [ "25mm_primer", 1 ] ], [ [ "chem_black_powder", 2200 ] ], [ [ "scrap", 4 ] ] ]
+  },
+  {
+    "result": "bp_25mm_slug_t",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "difficulty": 4,
+    "time": "10 m",
+    "qualities": [ { "id": "SAW_M", "level": 2 } ],
+    "components": [
+      [ [ "25mm_casing", 1 ] ],
+      [ [ "25mm_primer", 1 ] ],
+      [ [ "chem_black_powder", 2200 ] ],
+      [ [ "incendiary", 20 ] ],
+      [ [ "scrap", 4 ] ]
+    ]
+  },
+  {
+    "result": "25mm_casing",
+    "type": "uncraft",
+    "activity_level": "MODERATE_EXERCISE",
+    "skill_used": "fabrication",
+    "time": "2 m",
+    "qualities": [ { "id": "SAW_M", "level": 2 } ],
+    "components": [ [ [ "scrap", 1 ] ] ]
   }
 ]
diff --git a/data/json/itemgroups/Locations_MapExtras/locations.json b/data/json/itemgroups/Locations_MapExtras/locations.json
index b19e7ea514e13..da46dda3e8e75 100644
--- a/data/json/itemgroups/Locations_MapExtras/locations.json
+++ b/data/json/itemgroups/Locations_MapExtras/locations.json
@@ -65,6 +65,7 @@
     "id": "vfw_books",
     "type": "item_group",
     "items": [
+      { "item": "textbook_launcher", "prob": 5 },
       [ "mag_traps", 20 ],
       [ "manual_traps", 12 ],
       [ "trappers_companion", 2 ],
@@ -1554,6 +1555,7 @@
     "id": "cop_evidence",
     "subtype": "distribution",
     "entries": [
+      { "item": "textbook_launcher", "prob": 3 },
       { "item": "crackpipe", "prob": 8 },
       { "item": "weed", "prob": 10, "charges": [ 1, 5 ] },
       { "item": "joint", "prob": 10 },
diff --git a/data/json/itemgroups/Locations_MapExtras/locations_commercial.json b/data/json/itemgroups/Locations_MapExtras/locations_commercial.json
index 25e87d51a2e85..53f3ae6c91e11 100644
--- a/data/json/itemgroups/Locations_MapExtras/locations_commercial.json
+++ b/data/json/itemgroups/Locations_MapExtras/locations_commercial.json
@@ -657,6 +657,7 @@
     "type": "item_group",
     "id": "mil_surplus",
     "items": [
+      [ "textbook_launcher", 2 ],
       { "group": "mags_surplus", "prob": 400 },
       [ "freeze_dried_meal", 20 ],
       [ "chocolate_military", 20 ],
diff --git a/data/json/itemgroups/Weapons_Mods_Ammo/guns.json b/data/json/itemgroups/Weapons_Mods_Ammo/guns.json
index 35f11067e26ac..3aff7e90e491f 100644
--- a/data/json/itemgroups/Weapons_Mods_Ammo/guns.json
+++ b/data/json/itemgroups/Weapons_Mods_Ammo/guns.json
@@ -997,6 +997,7 @@
     "id": "guns_launcher_milspec",
     "//": "Factory manufactured grenade and rocket launchers (excludes improvised weapons)",
     "items": [
+      { "group": "guns_launcher_heavy", "prob": 20 },
       { "group": "guns_launcher_flame", "prob": 20 },
       { "group": "guns_launcher_grenade", "prob": 70 },
       { "group": "guns_launcher_rocket", "prob": 30 }
diff --git a/data/json/itemgroups/books.json b/data/json/itemgroups/books.json
index 9b7c37a2fa994..df093169db0e1 100644
--- a/data/json/itemgroups/books.json
+++ b/data/json/itemgroups/books.json
@@ -19,6 +19,7 @@
     "//": "Reference books about guns",
     "subtype": "distribution",
     "entries": [
+      { "item": "textbook_launcher", "prob": 5 },
       { "item": "manual_launcher", "prob": 5 },
       { "item": "manual_pistol", "prob": 50 },
       { "item": "manual_rifle", "prob": 50 },
@@ -77,6 +78,7 @@
     "//": "Military combat manuals and related books",
     "subtype": "distribution",
     "entries": [
+      { "item": "textbook_launcher", "prob": 20 },
       { "group": "book_gunmags", "prob": 100 },
       { "group": "book_martial", "prob": 100 },
       { "item": "manual_bashing", "prob": 40 },
@@ -336,6 +338,7 @@
     "id": "manuals",
     "subtype": "distribution",
     "entries": [
+      { "item": "textbook_launcher", "prob": 1 },
       { "group": "manuals_school", "prob": 424 },
       { "item": "manual_melee", "prob": 6 },
       { "item": "manual_cutting", "prob": 12 },
@@ -418,6 +421,7 @@
     "id": "textbooks",
     "subtype": "distribution",
     "entries": [
+      { "item": "textbook_launcher", "prob": 5 },
       { "group": "textbooks_school", "prob": 228 },
       { "item": "textbook_gaswarfare", "prob": 5 },
       { "item": "recipe_bullets", "prob": 8 },
diff --git a/data/json/itemgroups/main.json b/data/json/itemgroups/main.json
index 64d0e00560b75..d69ade5d5407a 100644
--- a/data/json/itemgroups/main.json
+++ b/data/json/itemgroups/main.json
@@ -91,6 +91,11 @@
     "id": "launchers",
     "subtype": "distribution",
     "entries": [
+      { "item": "25mm_autocannon", "prob": 1 },
+      { "item": "25mm_apds", "prob": 1 },
+      { "item": "25mm_apfsds", "prob": 1 },
+      { "item": "25mm_hei", "prob": 1 },
+      { "item": "belt25mm", "contents-group": "25mm_ammo", "prob": 2 },
       { "item": "mm1", "prob": 1 },
       { "item": "m79", "prob": 10 },
       { "item": "m320", "prob": 50 },
diff --git a/data/json/itemgroups/military.json b/data/json/itemgroups/military.json
index 7d841afe210ed..78d57758ab6cc 100644
--- a/data/json/itemgroups/military.json
+++ b/data/json/itemgroups/military.json
@@ -575,6 +575,10 @@
     "id": "military",
     "subtype": "distribution",
     "entries": [
+      { "item": "25mm_apds", "prob": 1 },
+      { "item": "25mm_apfsds", "prob": 1 },
+      { "item": "25mm_hei", "prob": 1 },
+      { "item": "belt25mm", "contents-group": "25mm_ammo", "prob": 1 },
       { "group": "mil_food", "prob": 1251 },
       { "group": "mil_armor", "prob": 575 },
       { "item": "m107a1", "prob": 1 },
@@ -852,6 +856,10 @@
     "id": "mil_hw",
     "subtype": "distribution",
     "entries": [
+      { "item": "25mm_apds", "prob": 1 },
+      { "item": "25mm_apfsds", "prob": 1 },
+      { "item": "25mm_hei", "prob": 1 },
+      { "item": "belt25mm", "contents-group": "25mm_ammo", "prob": 1 },
       { "item": "gau19", "prob": 5, "charges": [ 0, 100 ] },
       { "group": "mags_milspec", "prob": 40 },
       { "item": "flamethrower", "prob": 20, "charges": [ 0, 3000 ] },
diff --git a/data/json/recipes/nested.json b/data/json/recipes/nested.json
index 2bf2e20642dc0..eaad3976661ec 100644
--- a/data/json/recipes/nested.json
+++ b/data/json/recipes/nested.json
@@ -4165,7 +4165,7 @@
     "name": "firearm primers",
     "description": "Recipes related to constructing primers, the impact explosives used to initiate the combustion of gunpowder to launch bullets from firearms.",
     "skill_used": "fabrication",
-    "nested_category_data": [ "lgpistol_primer", "lgrifle_primer", "shotgun_primer", "smpistol_primer", "smrifle_primer" ],
+    "nested_category_data": [ "lgpistol_primer", "lgrifle_primer", "shotgun_primer", "smpistol_primer", "smrifle_primer", "25mm_primer" ],
     "difficulty": 4
   },
   {
diff --git a/data/mods/Generic_Guns/ammo/gg_ammo_migration.json b/data/mods/Generic_Guns/ammo/gg_ammo_migration.json
index 322fd66eea89e..535a8e2955df2 100644
--- a/data/mods/Generic_Guns/ammo/gg_ammo_migration.json
+++ b/data/mods/Generic_Guns/ammo/gg_ammo_migration.json
@@ -388,7 +388,7 @@
     "replace": "grenade_ammo_flare"
   },
   {
-    "id": [ "40x46mm_m433", "40x46mm_m651", "40x53mm_m430a1" ],
+    "id": [ "25mm_hei", "40x46mm_m433", "40x46mm_m651", "40x53mm_m430a1" ],
     "type": "MIGRATION",
     "replace": "grenade_ammo_hedp"
   },
@@ -414,6 +414,12 @@
   },
   {
     "id": [
+      "25mm_apds",
+      "25mm_apfsds",
+      "25mm_slug",
+      "bp_25mm_slug",
+      "25mm_slug_t",
+      "bp_25mm_slug_t",
       "40x46mm_slug_m118",
       "40x46mm_slug_m199",
       "40x53mm_slug_m169",
diff --git a/data/mods/Generic_Guns/ammo/gg_casings_migration.json b/data/mods/Generic_Guns/ammo/gg_casings_migration.json
index 9c791bc5b29c4..a9be4a45f02da 100644
--- a/data/mods/Generic_Guns/ammo/gg_casings_migration.json
+++ b/data/mods/Generic_Guns/ammo/gg_casings_migration.json
@@ -1,6 +1,13 @@
 [
   {
-    "id": [ "40x46mm_m118_casing", "40x46mm_m199_casing", "40x46mm_m195_casing", "40x46mm_m212casing", "40x53mm_m169_casing" ],
+    "id": [
+      "25mm_casing",
+      "40x46mm_m118_casing",
+      "40x46mm_m199_casing",
+      "40x46mm_m195_casing",
+      "40x46mm_m212casing",
+      "40x53mm_m169_casing"
+    ],
     "type": "MIGRATION",
     "replace": "grenade_casing"
   },
@@ -72,7 +79,7 @@
     "replace": "ammolinkrifle"
   },
   {
-    "id": "ammolink40mm",
+    "id": [ "ammolink25mm", "ammolink40mm" ],
     "type": "MIGRATION",
     "replace": "ammolinkgrenade"
   },
diff --git a/data/mods/Generic_Guns/firearms/gg_firearms_migration.json b/data/mods/Generic_Guns/firearms/gg_firearms_migration.json
index c501bab6f8b65..a91ebecb0e353 100644
--- a/data/mods/Generic_Guns/firearms/gg_firearms_migration.json
+++ b/data/mods/Generic_Guns/firearms/gg_firearms_migration.json
@@ -20,7 +20,7 @@
     "replace": "grenade_blooper"
   },
   {
-    "id": [ "mark19", "mark19_handheld" ],
+    "id": [ "mark19", "mark19_handheld", "25mm_autocannon" ],
     "type": "MIGRATION",
     "replace": "grenade_hmg"
   },
@@ -240,7 +240,7 @@
     "replace": "rifle_huge_double"
   },
   {
-    "id": [ "m2browning", "m2browning_handheld", "gau19", ],
+    "id": [ "m2browning", "m2browning_handheld", "gau19" ],
     "type": "MIGRATION",
     "replace": "rifle_huge_hmg"
   },
diff --git a/data/mods/Generic_Guns/magazines/gg_magazines_migration.json b/data/mods/Generic_Guns/magazines/gg_magazines_migration.json
index 468065e51b400..7ed7e4a17511f 100644
--- a/data/mods/Generic_Guns/magazines/gg_magazines_migration.json
+++ b/data/mods/Generic_Guns/magazines/gg_magazines_migration.json
@@ -1,6 +1,6 @@
 [
   {
-    "id": [ "belt40mm" ],
+    "id": [ "belt25mm", "belt40mm" ],
     "type": "MIGRATION",
     "replace": "grenade_belt"
   },