There's actually TWO models of Metal Tom. This one here is the FIRST one used by Hilda's forces. Note the Maxim MG08/15 aircraft machine gun on his RIGHT ARM.

About Metal Tom:
Unlike Tom himself, Metal Tom was created by BOTH Metal Sonic and Hilda, and acted the EXACT OPPOSITE of Tom. He kills, tortures, and slaughters many innocent lives. Unlike the Metal Series created by Dr. Julian Kintobor (Dr. Eggman's REAL name), Metal Tom has emotions and a personality.

As it says on the left side of the picture

"This is the FIRST used model of the "Metal Tom" series. Instead of the MG 42 Mauser machine gun, like on Model XXII, Model XV is armed with a Maxim/Spandau MG 08/15 machine gun with a 600-round ammo belt."

The Maxim had a lower rate of fire than the MG 42.

Metal Tom Model XV is to ME. Please Do Not use him without my permission.

Enjoy! ;)