Nice buck blammer.
Im betting your rifle has a MUCH slower twist than 1:28". The Sidekick/Huntsman likes a bullet in the 430-460 grain range. Mine don't even like 400 grainers, too light. Every rifle is an individual though, so you never know what you are going to get. With reduced loads, you might get the 350's to fly, but I doubt very well. Those 460's with 70 to 80 grains of 777, will go around 1.5" with peep/fire-sight, all day without swabbing between shots.