diff --git a/code/modules/projectiles/ammunition/_ammunition.dm b/code/modules/projectiles/ammunition/_ammunition.dm
index a9e4fa1646..b621033123 100644
--- a/code/modules/projectiles/ammunition/_ammunition.dm
+++ b/code/modules/projectiles/ammunition/_ammunition.dm
@@ -9,7 +9,7 @@
 	w_class = WEIGHT_CLASS_TINY
 	materials = list(MAT_METAL = 500)
 	var/fire_sound = null						//What sound should play when this ammo is fired
-	var/caliber = null							//Which kind of guns it can be loaded into
+	var/caliber = list()							//Which kind of guns it can be loaded into
 	var/projectile_type = null					//The bullet type to create when New() is called
 	var/obj/item/projectile/BB = null 			//The loaded bullet
 	var/pellets = 1								//Pellets for spreadshot
diff --git a/code/modules/projectiles/boxes_magazines/internal/_cylinder.dm b/code/modules/projectiles/boxes_magazines/internal/_cylinder.dm
index 538ac753e2..d8e53b2451 100644
--- a/code/modules/projectiles/boxes_magazines/internal/_cylinder.dm
+++ b/code/modules/projectiles/boxes_magazines/internal/_cylinder.dm
@@ -1,7 +1,7 @@
 /obj/item/ammo_box/magazine/internal/cylinder
 	name = "revolver cylinder"
 	ammo_type = /obj/item/ammo_casing/a357
-	caliber = "357"
+	caliber = list("357","38")
 	max_ammo = 7
 
 /obj/item/ammo_box/magazine/internal/cylinder/ammo_count(countempties = 1)
@@ -31,7 +31,7 @@
 		rotate()
 
 /obj/item/ammo_box/magazine/internal/cylinder/give_round(obj/item/ammo_casing/R, replace_spent = 0)
-	if(!R || (caliber && R.caliber != caliber) || (!caliber && R.type != ammo_type))
+	if(!R || (caliber && !(R.caliber in caliber)) || (!caliber && R.type != ammo_type))
 		return FALSE
 
 	for(var/i in 1 to stored_ammo.len)
diff --git a/code/modules/projectiles/boxes_magazines/internal/grenade.dm b/code/modules/projectiles/boxes_magazines/internal/grenade.dm
index 8b2ec9fca3..d6d338e8ff 100644
--- a/code/modules/projectiles/boxes_magazines/internal/grenade.dm
+++ b/code/modules/projectiles/boxes_magazines/internal/grenade.dm
@@ -1,7 +1,7 @@
 /obj/item/ammo_box/magazine/internal/cylinder/grenademulti
 	name = "grenade launcher internal magazine"
 	ammo_type = /obj/item/ammo_casing/a40mm
-	caliber = "40mm"
+	caliber = list("40mm")
 	max_ammo = 6
 
 /obj/item/ammo_box/magazine/internal/grenadelauncher
diff --git a/code/modules/projectiles/boxes_magazines/internal/revolver.dm b/code/modules/projectiles/boxes_magazines/internal/revolver.dm
index 982d22493f..a9cad1adc8 100644
--- a/code/modules/projectiles/boxes_magazines/internal/revolver.dm
+++ b/code/modules/projectiles/boxes_magazines/internal/revolver.dm
@@ -1,19 +1,19 @@
 /obj/item/ammo_box/magazine/internal/cylinder/rev38
 	name = "detective revolver cylinder"
 	ammo_type = /obj/item/ammo_casing/c38
-	caliber = "38"
+	caliber = list("38")
 	max_ammo = 6
 
 /obj/item/ammo_box/magazine/internal/cylinder/rev762
 	name = "\improper Nagant revolver cylinder"
 	ammo_type = /obj/item/ammo_casing/n762
-	caliber = "n762"
+	caliber = list("n762")
 	max_ammo = 7
 
 /obj/item/ammo_box/magazine/internal/cylinder/rus357
 	name = "\improper Russian revolver cylinder"
 	ammo_type = /obj/item/ammo_casing/a357
-	caliber = "357"
+	caliber = list("357")
 	max_ammo = 6
 	multiload = 0
 
diff --git a/code/modules/projectiles/guns/ballistic/revolver.dm b/code/modules/projectiles/guns/ballistic/revolver.dm
index c2206fcea8..ab9dd6d6a6 100644
--- a/code/modules/projectiles/guns/ballistic/revolver.dm
+++ b/code/modules/projectiles/guns/ballistic/revolver.dm
@@ -110,7 +110,7 @@
 /obj/item/gun/ballistic/revolver/detective/screwdriver_act(mob/living/user, obj/item/I)
 	if(..())
 		return TRUE
-	if(magazine.caliber == "38")
+	if("38" in magazine.caliber)
 		to_chat(user, "<span class='notice'>You begin to reinforce the barrel of [src]...</span>")
 		if(magazine.ammo_count())
 			afterattack(user, user)	//you know the drill
@@ -120,7 +120,7 @@
 			if(magazine.ammo_count())
 				to_chat(user, "<span class='warning'>You can't modify it!</span>")
 				return TRUE
-			magazine.caliber = "357"
+			magazine.caliber = list("357")
 			desc = "The barrel and chamber assembly seems to have been modified."
 			to_chat(user, "<span class='notice'>You reinforce the barrel of [src]. Now it will fire .357 rounds.</span>")
 	else
@@ -133,7 +133,7 @@
 			if(magazine.ammo_count())
 				to_chat(user, "<span class='warning'>You can't modify it!</span>")
 				return
-			magazine.caliber = "38"
+			magazine.caliber = list("38")
 			desc = initial(desc)
 			to_chat(user, "<span class='notice'>You remove the modifications on [src]. Now it will fire .38 rounds.</span>")
 	return TRUE