This has been done already, very successfully too.
It's the standard late 19th c. European colonial warfare tactic:
Equip a "flying column" with as much firepower as possible, march it off into hostile territory and the the enemy come to you in a defensive position. Auto-fire wasn't even required. Repeating rifles was almost always more than sufficient. Machineguns just made it that much easier.
1898 Battle of Omdurman, all (infantry) casualties of the Anglo-Egyptian army sustained after action, as they walked across the "battlefield", or maybe rather "massacre patch". No Sudanese warrior came withing 300 yards of the Anglo-Egyptian line of fire. 750 western casualties for 25.000 Sudanese.
1905-1906, the Maji-maji Rebellion, German East Africa, between 100 and 200 dead Europeans for up to 150.000 natives killed. Good use of machineguns there.