I feed my snakes in their enclosures. I have not been bitten yet.
As long as your hand doesn't smell like a mouse, you should be fine.
Just move slowly without any quick movements. Sometimes quick movements startle snakes to defensive strike.
Also, sometimes feeding responses are strong. So if you're uncomfortable with the snake coming at you, you can use a blunt object such as a paper towel roll or rolled up newspaper to block or redirect their heads.
Some of my aggressive feeders don't realize it's me right away and pose to strike. But once they realize there is no food, they back off.