My comments are assuming you get your BATF Form 1 approved...
It's going to take a lot of "tuning", if it can be done at all...
With the 930, the gas system uses some of the pressure from the friring of the shell to force the bolt back at the correct speed so that the empty shell hits the ejector inside the receiver with enough force to release it from the extractor and throw it out the ejector port. The gun then mecanically chambers the next round.
Because the barrel will be shorter you will have less pressure to begin with so you will need to open up the gas ports in the piston area that go into the barrel "just enough" to get the gun to function using the lightest load you intend to shoot.
