I have an 8X monocular. It is good for up to 50 yards with muzzle loading calibers. Meaning big ones, .45 to .60 and such. But for modern rifle calibers it is not very helpful. Power isn't everything, hand shake is a big factor.
My spotting scope is a Redfield 15-50X I mount on an old professional camera tripod. You can, literally, see a fly on paper at 100 yards with it.