Ostketten - You mentioned installed rifled barrels for accuracy, one of them many drawbacks of a round projectile is we have to add backspin for it to travel any resonable sort of distance. There is one company that makes rifles airsoft barrels, Tanio Koba. I installed one a while back in an AEG to see if it really made a difference, and to be honest after thousands of rounds fired, I couldn't see any chance in accuracy.