I don't recall how the SD comes into play for the formulas when used for RB's but I can tell you these things:
0.440" RB driven from a 36" bore with 80gr of 2F will enter the chest of a whitetail at 40yds, cut the boiler almost in half, penetrate at an angle to the opposing hind quarter and come to rest against the bone. Same ball & load effectively enters the WT nose at 30yds emptying the brain box through a 2.5" diameter hole in the rear. Same ball & load at 60yds goes through a WT boiler room taking out the boiler and lays under the hide on the opposit side.
0.575" RB driven from a 34" bore with 100gr of 2F will effectively take out one WT front shoulder and penetrate at an angle exiting through a 1.5" hole in the rib cage on the opposit side on a WT at 85yds then go another 10yds or so before burying itself about 2" deep in a pine tree. Same ball & load at 65yds will enter the WT's neck from dead front center at spine level and open a hole a foot plus long like a zipper where the spine used to be over the shoulders, no idea where it went from there. Same ball & load on WT 70yds out that suspected I was there somewhere punched through both shoulder bones with ease and without destroying all the meat (was supposed to be a boiler room hit not a shoulder breaker - he started turning to bolt)
I don't care what the math says, RB's work just fine.
"Carry the battle to them. Don't let them bring it to you. Put them on the defensive and don't ever apologize for anything."
Harry S. Truman