OK, I can solve this for you and even tailor it to your specific geographical location.
First, take the rifle down to the Forks, preferrably at night.
Face the widest part of the river.
Take it by the barrel and swing it as hard as you can.
Release the rifle ensuring that it flies as far into the middle of the river as possible.
Call the police and tell them you dropped your rifle in the river.
Go to the local gun store and buy a decent bolt rifle.