Charlie Brown, I have the same problem and am hoping someone will tell us how to fix it before hunting season! I have a Euroarms 1858 Enfield. I use 85 grains of RS Pyrodex and use Thompson Center Maxi Hunter bullets. My first shot does the exact same thing yours does. After my first shot, she is right on. Obviously, I can't fire the gun before I go to my blind in the morning. Anyone have any ideas?