ORIGINAL: The Rifleman
My dad would say - How Dumb are You?
You cannot use a rifle scope on either a Muzzleloader or a Shotgun.
A rifle scope is designed for a Rifle ONLY!
There is different harmonic's between a rifle and a shotgun and that is what broke your scope. The different type of recoil between the two will break almost any type of rifle scope - even a Leupold.
Besides that - you do not need a Bushnell Elite 3200 on a Shotgun!
Even with a rifled slug, your effective range is still less than 200 yards.
If you would have PAID someone to mount your scope for you - that knew something about guns and scopes, they would have advised you not to do it and would also had advised you to buy a shotgun scope for your muzzleloader or shotgun and not a rifle scope.
Play dumb, send it back. Bushnell will replace it.
Go out and BUY a shotgun scope and put the rifle scope on a rifle and you will not have anymore problems.
Rifleman, let's try and not be rude to each other, especially when our info is not accurate. There are only 2 differences between a rifle scope and a muzzleloader scope. One is paralax, (which HEAD001 pointed out) and minute of angle adjustment. A rifle scope has about 30 minutes, or inches of adjustment and a shotgun/muzzle scope has about 75. This is due to the fact that they do not typically produce the flat trajectories you will see from a rifle. Now call any scope manufacturer and ask them if their scopes are made to different recoil tolerances depending on what gun they are going on and you will get a resounding NO!