I started deer hunting in 1964 with the rifle. After taking a fair number, the buck fever went away. Killing a deer became rather routine. Then I took up bow hunting, and now, for almost 30 years, have only used the bow. The buck fever once again became an issue. I think it has to do with distance and noise to a large degree. You are more likely to be seen and/or heard, so jumping the string is a likely result. This tends to condition us to be antsy. Recurrence and familiarity are, for me, the most likely cure for nervousness in any tense activity. I have a lousy release, so I spend a lot of time shooting from very close ranges, concentrating solely on a smooth release. On the last deer I killed, I was thinking about a smooth release all the way through, and the buck fever did not kick in till after the shot. However, I don't ever want buck fever to completely go away, because that is the most immediate indication of the excitement of the hunt - I just want to handle it well.