Bushnell are junk and so are Vortex products. The best thing about them is the warranty and unfortunately if you buy one you're likely to need to use the warranty.
I've owned numerous Bushnell scopes and four Vortex scopes and I will never waste my money on them again.
Had a Bushnell Elite 6500 and the glass was garbage. Look through one at an object 800 meters away then through a Sightron or other scope with quality glass and the difference is immediately obvious. Vortex has better glass but they're built poorly and most don't last.
Of the four Vortex scopes I've owned two of them needed repair work. Not a good failure percentage for $800+ optics (they were all Viper PST series).
OP. I have a Derya Mk-12, throw an Aimpoint PRO on it ($500 or less on EE) and your problems will be gone. Mine has run a couple hundred rounds of various 12ga including 3 inch buck and slugs with zero issues.