That is a Leupold one piece base I had with turn in front ring and windage adjustable rear ring. Its on a .204 so I didn't consider a 6 screw set up for the base. Works extremely well for prairie dogs. The rings are medium height Redfields left over from an old rifle project. It has been my experience that with most set ups using a 44mm objective lens scope or smaller that med rings works very well. It leaves >.125" between scope and barrel. We use no hammer extension on that rifle......the back rifle does have a ***** hammer extension because its an original Contender and different scope and its a little tighter between the two.
One thing to consider is that we mount the scope back a bit because my son likes that for shooting from our table. Its his gun so I set it up the way he likes it
