I have a Mossberg 50164, which is essentially the 500, but came with interchangeable barrels, one rifled and one shot barrel. I sold the shot barrel and have no intentions of ever taking off the rifled barrel. It is NOT drilled or tapped. There is a plate that fitson top ofthe receiver and goes over both sides of the receiver, where it is bolted to the sides of the receiver. The top of the plate is elevated off the receiver to allow for open sights beneath the scope.


Here's what I did...

I adjustedthe elevation of the scope "up/down" back to roughly the middle from all the way "up," took off the tops of the rings and put a shim under the back, which consisted of a business card folded over one time, cut to fit the width of the bottom ring. Then I realigned the rings up with where they were before (you could see"lines"in the paint on the scope where the rings had been tightened), checked to see that the cross hairs were vertical and horizontal and not on some slant, and tightened up the screws again.

Now I need to shoot it again and see if it worked. Do you think two business card thicknesses will do the trick?

Thanks for all the help!