27 MOA is 7.8 mils, so you should be okay.
Steiner lists the 3-12x50 as having 19.5 mils of elevation adjustment buy my guess is that's restricted by the double turn knob and there is more travel than that in the erector assembly.
Joe
Somewhere I saw a spec sheet indicating 30 or more mils of total elevation travel available, and then the 19.5 that you can use once zeroed. It would be very strange if a 12x scope with a 34mm tube had only 19.5 mils of total elevation travel, and the 19.5 stop wouldn't make sense if that maximum travel was only 19.5, since most rifles would end up stopping at less than 19.5 one zeroed.