bigbulls...

i do agree you don' t need a premuim bullet. but up in maine and i bet where BIG DUCK EXTREME is the deer get real big. for those velocities i think it is better to use a premuim bullet. after all you only really get one shot at a deer that is a monster . ( i am still waiting ).
i think if not using a premium bullet to use a 180gr. core-lokt out of the 30-06sprg or like woodseye stated the 150gr. core-lok' t.

you also might want to try the federal classic HI-shok SP' s for your 270win the 140gr. never worked in my gun, but the 130gr and the 150worked well.