Fighter/15th/Sharpshooter

Maneuver

Starting from 15th level, you can always escape to a better position. For every 5 feet you move, you can expend 1 stamina point to ignore difficult terrain and prevent that movement from provoking any opportunity attack.

Ammo Expert

At 15th level, you become an expert with woodworker's tools. Any attack you make that uses ammunition ignores damage resistance, and your ammunition is always considered a magic weapon for the purpose of overcoming damage immunity.