The Leupold VX-Freedom 3-9x40 Muzzleloader UltimateSlam is our top recommendation for deer hunting since it’s got higher magnification, which is better for the more open areas in which deer hunting typically occurs. It’s designed explicitly for shotguns and muzzleloaders and is an excellent choice for slug guns.  The excellent light transmission is also ideal for the morning and evening when deer are most active.