I have what I consider a basic understanding of pcp tuning and modification. I just got into this dark side about a year and a half ago. I have had great success tuning my marauder with nervousstrig's help as well as motorhead, bigragu, and a few people that don't like being mentioned. In any case a real problem rifle turned into a sweet shooter. Actually my reg has had the same problem yours had just out of the box. In my case shooting 500 cph from Walmart broke it in and now I have an extreme spread of like 5 fps over 70 shots or something like that. Its really quite impressive for a crosman reg. I would consider that shot string normal but in need of tuning. I've had 2 regs and they both did that and both fixed themselves. Good luck.