Gun(and one magazine) volume audit for 9x18 and 7.62x25 (#39337)

* Audit Makarov PM
* Audit Tokarev TT-33
* Audit PPsh-41
* Throw in a magazine audit

data/json/items/gun/762x25.json

@@ -6,8 +6,8 @@
     "reload_noise_volume": 10,
     "name": { "str": "PPSh-41" },
     "description": "The Soviet-made PPSh-41 is a mass-produced selective-fire submachine gun.  It has a relatively high rate of fire.",
-    "weight": "3630 g",
-    "volume": "1750 ml",
+    "weight": "3640 g",
+    "volume": "2873 ml",
     "price": 280000,
     "price_postapoc": 2250,
     "to_hit": -2,
@@ -49,7 +49,7 @@
     "//": "And it's therefore expensive.",
     "description": "The Tokarev TT-33 is an antique Russian semiautomatic pistol, famous for its durability, accuracy, and uncomfortable grip angle.  It was chambered for the 7.62x25mm due to the popularity of the C96 pistol among Russian revolutionaries.",
     "weight": "870 g",
-    "volume": "500 ml",
+    "volume": "251 ml",
     "price": 100000,
     "price_postapoc": 1250,
     "to_hit": -2,

data/json/items/gun/9x18.json

@@ -8,7 +8,7 @@
     "//": "10 and 12-round magazines exist, but were made for the newer PMM, and are not compatible with the old PM.",
     "description": "The Pistolet Makarova was developed by the Soviet Union to replace the WWII-era TT-33 pistol.  It uses the 9x18mm cartridge, which remains in use among various former Soviet countries.",
     "weight": "730 g",
-    "volume": "250 ml",
+    "volume": "346 ml",
     "price": 25000,
     "price_postapoc": 2000,
     "to_hit": -2,

data/json/items/magazine/762x25.json

@@ -6,8 +6,8 @@
     "name": { "str": "PPSh 71-round drum magazine" },
     "//": "Provisional.",
     "description": "A high-capacity drum magazine for the PPSh-41.",
-    "weight": "1387 g",
-    "volume": "750 ml",
+    "weight": "1760 g",
+    "volume": "911 ml",
     "price": 7000,
     "material": "steel",
     "symbol": "#",