There is a significant difference in accuracy between unloading an entire clip in continuous fire, and firing in short bursts from a crouching position.
View a summary of weapon accuracy and damage stats together with some general tips on using weapons.
The Thompson provides a higher body health damage than the MP-40, but is not quite as accurate.
The MP-40 is a good all-rounder. Its more accurate than the Thompson and has a slightly higher rate of fire.
The Sten has incredible accuracy, even giving reasonable results when fired continuously and the Sten's rate of fire is much greater than both the Thompson and MP-40.
The Mauser is an excellent weapon for taking out enemies from a long distance, without putting yourself at risk. The mauser is powerful and accurate.