Assuming quality optics on a quality rifle, up to what yardage do you confidently shoot 3x magnification to? Assume field conditions not bench shooting. Let's also assume a 10" kill zone.
300 yards assuming I have time to collect myself, lean on a tree and/or get three or more points of contact with the ground to stabilize myself. Offhand it wouldn't matter if I had a 3x or 16x, I'm probably looking at 100 yards or so. My first deer rifle had a Leupold 1-4 variable scope on it that I killed a pile of deer and probably 100's of ground hogs with it at all sorts of ranges out to 300.
At a 10" target probably 150 or so off hand. If could lean kn something or get into a more stable position besides standing probably closer to 300.
Love it so far I don't have it completely zeroed yet cause I had the gf with me, but it's really good glass for the $$. Deff look into the Nikon app "Spot on" 200 yard zero, 300 yd shot, 62gr xtac
500 meters on a calm day, 300 with anything that resembles wind. With an M4. 308 winchester, im comfortable out to 800. Prone supported. But i've gotta have target turrets, no kentucky windage.
I thought my initial idea had to be wrong, I couldn't picture you slug gun hunting, but a 3x on a slug gun would be extremely versitile. That is my only frame of reference, and with a flat shooting gun I'd shoot to 125-150 yds, I suppose with a more accurate rifle & a 3x 200-250 should be comfortable with a good rest. For my shooting abiilties.