I also bought a Navy Arms (rossi) several years ago that didn't eject properly and would sometimes drop the spent case back into the action. Solution was I called Navy Arms and they sent me a new ejecter and extractor. The actual problem was Rossi had cut the face of the ejector too large for the case head and this allowed the 38 special cases to slip down out from under the extractor during rearward movement of the bolt causing poor extraction. Get a new ejector, and with the bolt out and the spring out, put the ejector in the bolt and with an empty cartridge scribe the deminisons of the 38 or 357 case head (using and empty) and mill out that area of the ejector. It will solve the problem.
Side note; if you will watch the process by opening the action slowly you will see that the ejector holds the 357 case tightly against the top of the chamber until it clears it, ejecting the spent or live cartridge. This should also be the case with 38 special but, because of above described problem isn't. Good luck,