The Grease Gun primary weapon in Call of Duty: WW2 is a slow firing, accurate submachine gun. The Grease Gun is most effective when you are at medium range and when you suprise enmies in that range. It is also important to stay mobile, otherwise assault rifles will easily overwhelm you at that range. This can be done by using hipfire and strafing whilst you are shooting. To achieve that use steady aim, which makes the Grease Gun more accurate when firing from the hip. To increase the damage output use rapid fire. To be able to suprise enemies use the airborne division which lets you attach a supressor to the Grease Gun and increases your mobility. Use the hustle basic training to reload faster which will help you when you are close to enemies.
Sometimes you need to move through open spaces to get into the Grease Gun’s desired range. Use smoke grenades to cover your advance. Use your favorite pistol secondary for when you run out of ammunition. Here is the complete best class setup for the Grease Gun..
As found on Youtube