I had my CZ 452 varmint out and was enjoying the huge improvement that the YoDave trigger kit made. It was shooting nice little groups then all of a sudden began vertical stringing - like 3-4". Windage is fine but the vertical is whacko. My gunsmith friend thinks it's the scope. Everything is tight....? Before I start messing with a very good shooting rifle I'd appreciate any ideas /input you all may have to offer.
