I have read several places that triple seven powder has a limited shelf life. Could this change the point of impact out of an inline rifle with powder that is only a year and a half old? This year I sighted my inline in with loose triple seven powder dead on at 100 yards in October for the early season. I took this gun out prior to rifle season to check it at the range and found my shots were still on left and right but were impacting about 8 inches high at 100 yards. Has anyone else had this experience? Could my powder have drawn moisture over time and gone bad (powder is roughly one and a half years old)? I have a quality scope on my inline so I don't think the scope is the issue. I also realize the shooter could be the problem, but I had just finished shooting less than an inch group with my regular deer rifle so I don't think that is the case either. Does anyone have any ideas as to what could cause this shift to a higher group?