Is that first one the MG42 or the more modern MG3? Basically the same machine gun, but the MG3 is calibred to 7.62mm NATO standard, and the wooden stock has been replaced with a black plastic one. I was trying to tell by the ammo belt, but I couldn't really.
No, the rate of fire is approximately the same between the two. The only significant difference is a slight reduction in calibre for the MG3. The earlier MG34 had a slower max rate of fire of around 750-800 rpm.
A machine gun linked more with WW1 that was used considrably in WW2 was the Old US designed Lewis gun speaking to some body who actually used one in anger he said that apart from a few stoppage problems he found it a pretty good weapon as it only weighed 12 kg it could be fired from the hip. On D-day as a group of LCA's approached the beach a Spandau open fire on the eight landing craft, immediatley all eight boats emptied their pans of ammo at the pill box slit. With a quite reasonably 600 round per minute rate of fire and 97 round magazines fitted nearly 800 bullets peppered the slit in just over 6 seconds The MG42 ceased firing.