RE: Nikon Monarch, Buckmaster and Leupold vx3
the biggest i own is 14x, so that's as far as I'm comfy with....at 14x, for hunting rigs I can't imagine having anything over 14x or 12x, a 500-600yd shot is far, not sure when I'll need to shoot past 600yds.
If I were doing exclusively long distance shooting, and had time to get setup, I may consider a bigger scope, but 14x you can lose game/hard to get in the crosshairs maxed out...power.....
my swaro is 3-12, great range IMO, if not perfect.
tons of guys have 3-9x and would shoot 500yds+
12 or 14x makes it easier, past that I think trouble can arise.... but if its a specialty rig where you plan to only shoot far, no close shots, then maybe an 18x.....i just don't forsee ever having a scope that big.