Was shooting my k80 two days ago and when I shot at doubles, I found that the second shot (top barrel) trigger pull was noticeably heavier than the first shot bottom barrel trigger pull. Took the stock off las night and fluid and air cleaned the internals very thoroughly. Then I spray lubricated everything and put the stock back on. Tried the triggers again many times with the barrel on; still have the same heavier trigger for the top barrel. All springs and all internal parts appear to be perfect. Anybody know what now is causing the major difference in trigger pull before I have to send the gun out for repair?