Based on the most poular bullet weight for each rifle you mentioned the results are:
30:30 10.6 ft. lbs.
308 Win 15.8 ft. lbs.
270 Win 16.5 ft. lbs.
30:06 20.6 ft. lbs.
45:70 23.9 ft. lbs.
12 Ga 2 3/4" and 3" 17-54 ft. lbs.
20 Ga 16-35 ft. lbs.