Did the Wehrmacht have anything as heavy hitting as the .50 cal?

Heavier.

On aircraft the German's preferred the MG151/15 cannon, a shell-firing gun using the 15x96mm cartridge (compared to 12.7x99 in the Browning) introduced in 1940. This was soon replaced though by the MG151/20 which increased the caliber to 20mm by the simple expedient of necking out the case to accept the projectile from the Oerlikon 20mm MG FF gun.

Germany also used the MG131 in 13x64B caliber primarily as a flexible mount (defensive gun) but also used as fixed armament in the Bf-109 and FW-190. This was less powerful than the M2 Browning.

The German ground forces went straight from rifle caliber (7.92mm) machine guns to 20mm shell-firing cannon, skipping the heavy machine gun altogether. The 20mm guns, firing a powerful 20x138B cartridge required heavier and more complicated mountings but were far more lethal.

they had the MG151 on various AAA platforms late in the war. not nearly as widespread as the M2, though. german infantry had to do with the MG42 on a tripod in the role of heavy MG.

also, the smaller MG 131

http://en.wikipedia.org/wiki/MG_131_machine_gun