Getting on a 1.5-2.0MOA target at any range with a 10X scope isn't some kind magic.
The mil-dots subtend just .2MIL which is ~7.5" at 980yds. The actual crosshairs subtend half that. So pasting a reticle on a target that is 4-6 times larger than your crosshair just isn't that difficult. Now can you count hairs, no. Can you put a round on target, yes you can, and that's not a guess. (grin)
I run my 6x scopes out to 5 and 600yds on MOA sized targets and larger. You don't need a target to fill your field of view to make well placed hits. I couldn't imagine not being able to shoot a 'chuck at 400yds with a 12x scope. Though not all glass/reticles are created equal and YMMV.
I don't know where you're from but we are talking woodchucks here.....and they ain't that little.