diff --git a/lua/entities/acf_gun/init.lua b/lua/entities/acf_gun/init.lua
index 9dbaa243..ebae4837 100644
--- a/lua/entities/acf_gun/init.lua
+++ b/lua/entities/acf_gun/init.lua
@@ -32,7 +32,6 @@ local function UpdateTotalAmmo(Entity)
 end
 
 do -- Spawn and Update functions --------------------------------
-	local ModelData = ACF.ModelData
 	local WireIO    = Utilities.WireIO
 	local Entities  = Classes.Entities
 	local Weapons   = Classes.Weapons
@@ -114,14 +113,13 @@ do -- Spawn and Update functions --------------------------------
 		return Result
 	end
 
-	local function GetMass(Model, PhysObj, Class, Weapon)
-		if Weapon then return Weapon.Mass end
+	local function GetMass(Caliber, Class, Weapon)
+	        if Weapon then return Weapon.Mass end
 
-		local Volume = PhysObj:GetVolume()
-		local Factor = Volume / ModelData.GetModelVolume(Model)
+	        local Factor = Caliber / Class.Caliber.Base
 
-		return math.Round(Class.Mass * Factor)
-	end
+		return math.Round(Class.Mass * Factor ^ 3) -- 3d space so scaling has a cubing effect
+		end
 
 	local function UpdateWeapon(Entity, Data, Class, Weapon)
 		local Model   = Weapon and Weapon.Model or Class.Model
@@ -190,7 +188,7 @@ do -- Spawn and Update functions --------------------------------
 		local PhysObj = Entity.ACF.PhysObj
 
 		if IsValid(PhysObj) then
-			local Mass = GetMass(Model, PhysObj, Class, Weapon)
+			local Mass = GetMass(Caliber, Class, Weapon)
 
 			Contraption.SetMass(Entity, Mass)
 		end