Revolver caliber changes; .357 revolvers can now also load .38 but not vice-versa.

Effectively it means you can load .38 rubber into a .357 revolver to make it less than lethal, or use the various different .38 ammo types.

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