MG34
The MG34 was the fastest shooter before Hitler's Buzzsaw(MG42) arrived and then replaced the MG34.
The MG 34 could use both magazine-fed and belt-fed 7.9 mm ammunition. Belts were supplied in a fixed length of 50 rounds, but could be linked up to make longer belts for sustained firing. A 250 round belt was also issued to machine guns installed in fixed emplacements such as bunkers. Ammunition boxes contained 250 rounds in five belts that were linked to make one continuous 100 round belt and one 150 round belt. The assault drums held a 50-round belt, or a 75-round "double drum" magazine could be used by replacing the top cover with one made specially for that purpose. A gun configured to use the 75-round magazine could not be returned to belt-feed mode without changing the top cover again. All magazine-feed MG 34s had been withdrawn from infantry use by 1941, with some remaining in use on armoured personnel carriers. Like most machine guns, the MG 34's barrel is designed to be easily replaced to avoid overheating during sustained fire. During a barrel change, the operator would disengage a latch which held the receiver to the barrel sleeve. The entire receiver then pivoted off to the right, allowing the operator to pull the barrel out the back of the sleeve. A new barrel would then be put in the back of the sleeve, and the receiver rotated back in line with the barrel sleeve and latched. The entire process took just a few seconds when performed by a well-trained operator, causing minimal downtime in battle.