Update data/json/items/gun/50.json

Co-authored-by: Maleclypse <[email protected]>

data/json/items/gun/50.json

@@ -153,7 +153,7 @@
   {
     "id": "bfg50",
     "copy-from": "rifle_manual",
-    "looks_like": "modular_ar15",
+    "looks_like": "m107a1",
     "type": "GUN",
     "name": { "str": "single-shot .50-caliber rifle" },
     "description": "Relatively trim as far as .50-calibre rifles go, this single-shot firearm was a reasonably affordable entry-level gun for civilians wishing to play with some very large, very punchy toys.  Now, at the world's Armageddon, it would be wise to make that singular round-capacity count on some high-priority craniums.",