Swede - They are already performing this type of operation on a lot of the new AR models out there. Check out the H&K 416/417 as a leading example at the moment. Both are piston driven, and the piston is sealed to eliminate the gas tube "clogging" & the chamber "fouling" of Eugene Stoner's Design...
So, in answer top your question, yes. It's possible and it is in common practice on several new models. But, they are expensive as all hell here in the states and we can't even get access to the H&K stuff - but perhaps you could sell your right arm, buy one and give us all a range report?
JD