Ok for the price - SightMark Bubble Level Rifle Scope Ring

I've used the SightMark Bubble Level twice on my new precision rifle and scope. Both times after carefully leveling at home, the bubble level apparently rotated during firing at the range and foiled my efforts to zero my new scope. When checking at home, I found my scope was dead level relative to my rifle's mounting rail but the bubble level was not. I'll give it another try but will likely go with a more expensive level.