hi im new to the forum.i just got my first gun.it is a h&r ultra slug hunter single shot with the ultragon rifling and bull barrle.i was wondering about the scope i am looking at.it is a new bushnell DOA shotgun scope at cabelas.it says to sight in at 100yrds and the 50,150,200 yrd crosshairs should be on the target to.any input be great thank you