Gene, I gave up on my new .22 Marauder and sent it back to Crosman today. I think I eliminated all possible causes of its inaccuracy except the barrel. If your barrel was made using the same tools and process, at approximately the same time as mine was, then yours may have the same problem mine had.
If Crosman is out of good barrels and can't fix mine, I'm leaning toward buying a Lothar Walther barrel for it.
Dale