Chulain,
May be missing something here, but yeah, you can, but .... without verifying your shot placement afterwards, you aren't "sighted in" by a long shot.
Too, having your cross hairs set at where the bullet hits (at 100 yds anyway), you're missing a big advantage of using the bullet's trajectory & what's known as "maximum point blank range."
Figure for a deer, the vital zone is 6" (up & down, diameter, whatever) setting the scope to throw the bullets 2" high at 100 yds (I actually prefer closer to 3" depending ...) you're (what Art said) ....
Sighting dead on at 100, you're likely to be a couple inches low at 200 & a foot or better at 300 .... better to tweak your scope a bit & use the arc of the bullet to your advantage.
Would have to run a 150 through the ballistic software to give "known #s," but close enough for arguin' with strangers ...
Like I said, may have misunderstood .....