I am wanting to get a vulcan 3 in .30 long to shoot slugs and im liking the dnt 5x20lrf the vulcan 3 has a 20moa built in rail will that be sufficent to get me out to 150 yards with crosshairs relatively centered would also be plinking at 25 to 80 yards im just wondering if ill need an adapter to keep a good sight picture relating to crosshairs