You are shooting a relatively fast, modern compound bow at 70 pounds with a 31 inch draw length. That, in and of itself, screams penetration to me. The only variable you left open is your arrow weight. You mentioned "carbons" but not what size/type or their weight for that matter. Assuming an appropriate spine for your setup I would wager your arrow weight with most ICS style carbons to be around 420-450 grains. Assuming an arrow speed of at least 275 fps would yield a KE figure, at the bow, of at least 70 ft. lbs. That is plenty of KE for penetration at moderate ranges. Out at 60 yards, assuming perfect conditions, I would imagine that you would still get good penetration assuming a cut on impact or chisel style point broadhead.