Re: Magnification for shooting @ 600 yards
It sounds like you may want to do a fair amount of shooting groups out to 600 yd. This type constitutes the bulk of my shooting and I definitely want more mag for that than what most others listed above. I have NF 3.5-15x50 F1, 5.5-22x50, and a new 8-32x56 I purchased for F-class comps. I just ran the F1 at 600 the other day shooting a black 18" target with a red 1.25" bull and for me, 15x is barely enough mag to see the holes at that distance. I use the 12" or 18" Shoot-N-See targets and I usually cover up the yellow lines and numbers with a fat black Sharpie, leaving only the red bull. This is because a shot on the line can be very difficult to see.
I'll admit that my eyes aren't what they used to be, but spotting .308 holes in a splatter target at 600 using 15x is at the extreme limit of what I can see. So for that purpose, I do much better with the 5.5-22x or 8-32x. There are definite trade-offs to using the higher mag such as exit pupil, FOV, etc. But if you want to spot holes at 600, 9x <span style="font-style: italic">may</span> not be enough, depending on how good your vision is. On the other hand, that is really what the spotting scope is for.
Unless the mirage is really bad, I can easily spot the holes using 22x (or higher), so only rarely do I actually <span style="font-style: italic">need</span> to use the spotting scope with either of the higher mag scopes. However, 15x is pretty iffy for me in that context, even with the splatter targets. If you want less mag on a higher power scope, you can dial back under the right circumstances, but if you want more mag and your scope is maxed out, not much you can do. Just something to keep in mind when thinking about your intended uses and deciding what scope will best suit your needs.
