Yes. The bolts of the two barrels were linked by a yoke, so that one of them was forwards while the other was back. This meant that the recoil of one bolt drove the other forwards. It was just getting into service at the end of the war. It was neat, but the gun was bulky and heavy and wasn't really much better than, say, a twin-Lewis mounting (possibly worse, in that if a round failed to fire the Gast stopped working, whereas with twin Lewis only one would stop). It was looked at with interest after the war, but no-one copied the idea until the 1950s when the USSR introduced the famous 23mm GSh-23. That differed in various respects, though, including being gas rather than recoil powered.
