What appears to be a Grand Power K100 (judging by the safety lever) standing in for a K105 R appears in the campaign as the "GP105".
Shotguns
Metal Storm MAUL
The campaign's MSBS Grot can be found with an underslung Metal Storm MAUL shotgun.
Submachine Guns
Heckler & Koch UMP45
KRISS Vector
The KRISS Vector appears as the "Super V". The campaign version is modeled after the Gen 2.1 Vector, while the multiplayer counterpart is the Gen I model.
The 2015 prototype of the AK-12 was seen in a trailer, though it doesn't seem to be present in the final game. It was actually modeled after an Airsoft replica, as evidenced by the selector markings, with the firing positions being white and the safe position being red, as opposed to the other way around.
The FB MSBS Grot C appears in the campaign as the "MAR-M1".
IWI X95
The IWI X95 appears in the campaign as the "MTR-95".
"Kalash-105"
The campaign-exclusive "Kalash-105" is a hybrid of the AK-12 (production version) and the AK-105. It has most visual features of the AK-12, but has the traditional trunnion-mounted rear sight of earlier AK models like the AK-105, and a custom top rail and handguard. The barrel length is between the AK-12 and the AK-105, and the weapon is depicted with an ambidextrous charging handle.