And the MP44 was the first official assault rifle*, chambered in 7.92mm
kurz (short). It was first introduced for the Battle of the Bulge and was highly effective (though when placed in the hands of green recruits, it was captured with the packing oil still fresh on it never having been fired!). The MP44 was designated as such (Machine Pistol, don't know the German offhand) to fool Hitler since he forbade the continuing development of the assault rifle when it was first presented to him. The designation was later changed to SG44 (
Sturmgewehr, as noted above -- "storm"="assault"

after Hitler realized its effectiveness and became enamoured with it.
I could have told you that Kalashnikov wasn't involved with the design of the M16 -- the M16 wouldn't have sucked so badly for so long if he had helped design it.

The AK-47 is arguably the best assault rifle made to date for its longevity, effectiveness, ruggedness and manufacturing ease. You don't hear much about its successor, the AK-74, but it's a nice gun, too -- chambered in 5.45mm, IIRC (look for the plastic magazines).
Ah, all this useless knowledge.
*Contrary to what the gun grabbers say when they called the M1 Garand an assault rifle several years ago!!