Originally Posted by dmax1800
...Is the 15-45 with the SX-1 enough magnification at 300 yards, or do I need to go to the 20-60 even though it is 80mm objective? I've also seen good reviews of the Nikon Prostaff 5 16-48x60 scope. Which is better for 300 yards???
In my experience the extra magnification of an 80 mm scope only gives a larger blurry image at 300 yards because of turbulence. I don't think you will see any more detail with an 80 mm scope than with a good 60 mm scope. On very overcast days, or briefly at dawn and dusk, when the turbulence is low, the bigger scope will have better resolution. Otherwise, you have the cost and bulk of the the bigger scope, with none of the advantages.
I'm not very impressed with any of the Nikon spotting scopes. At one of the ranges I use, the 80 mm Prostaff is set up next to the 60 and 80 mm SX-1 scopes. On a good day, when the turbulence is low, the resolution of the 60 mm SX-1 is comparable to the Prostaff. Although all three scopes have plastic bodies, mounts and eyecups, the two SX-1 scopes are holding up well to daily use, but the Prostaff is not. On the Prostaff the base is broken and the eyecup won't rotate easily because an internal piece is broken. The SX-1 scopes also have better eye relief.
It's difficult to say the you will see .30 holes at 300 yds because visibility depends on contrast. If you have dark holes in light colored paper, or bright holes in dark colored paper, you should be able to see them with the 60 mm SX-1 scope. If you cannot, try changing targets.