A lot of players and posters on this forum have been complaining for some time that the MGs are severely underpowered in the accuracy and effectiveness departments. I'm more of a rifleman and haven't been that good with them myself but last night I gave them a whirl on Pavlov's house, a notoriously hard map to use an mg on without getting picked off.
Now most of you might already know this, but when you press the shift key without moving, you zoom in. I suppose this feature is useful for spotting targets at a distance. You can also use this ability temporarily with iron sights as a supposed "holding your breath" shot.
What I don't think a lot of people realize is when you have the MG deployed, you get unlimited zoom which allows you to directly compete with riflemen.
I would setup in different locations around the map and simply hold down the shift key and completely suppress the entire area. Enemies would hear the machine gun fire and pop up to take a shot at me and I would just fire a couple single shots and drop them.
Now keep in mind, im not that good with the MG34. I'm an average shot at best. The advantage I had came from the ability to completely stabilize the gun and the zoom to identify targets.
I tried this same feature on commissar's and it works just as effectively with the DP.
I was still killed plenty if I deployed in stupid positions where my firing lane was too wide. My position still mattered, but whatever I decided to cover, was covered.