A POI comparison between the 2 bullets at 100 yards will tell you which has the superior BC.... Since they are impacting at the same point at 200 yards, if they also impact at the same point at 100 yards, and you know the 113 gr. has a 20 fps advantage at the muzzle, then you will know that the 134 gr. BBT has a better BC, since at those 3 points it has the same trajectory....

If the POI at 100 yards is not the same, then you will need quite accurate measurements of the POI at both distances, from a common aim point, plus the MVs, to calculate the BCs.... ChairGun can do the math for you.... Note, your results will only be as good as your POI measurements....

Bob