If your rifle was sighted in last year, don't automatically assume that it will be ready to use this year. I recently went squirrel hunting. I took my .22 rifle which was shooting dead on at 50 feet last year. After missing four squirrels, I knew something was wrong. 

Quickly, I set up a target and shot at it. The gun was shooting two inches high at 50 feet. After making some adjustments, I went back to hunting and shot a limit of squirrel. 

I don't know what causes it, but a rifle can change its point of impact after setting a year. Take a few practice shots to confirm that it's still zeroed in and you can remove all doubt and hunt with confidence.

The best hunters leave nothing to chance. You owe it to yourself and the game you pursue to be sure that your rifle is hitting precisely where you're aiming.