BC won't play a big role in most handgun bullets anyway. If you want better BC then for the BT tipped bullets meant for lever actions.Generally you are looking at 1700-1850fps at best. At these velocities BC doesn't really have time to be a factor, and you are limited to about 150yds effective point blank range, with a 125yd zero.
Unless "loaded for bear" or carbines.Both rounds will achieve maximum velocity in a barrel less than 16," the result of limited powder capacity.
I prefer the 16" barrels on just about anything. Both of my lever action .44 Mags are 16", but the Winchester takedown Trapper is an octagon barrel so much heavier than that Rossi. That's okay as the Winchester is a safe queen and the Rossi a truck gun.But some like the balance of the 20" over 16".
I feel the .44 Mag is a more versatile cartridge than the .357 Mag. E.G., if I had to, and I had the right ammo and the distance was right (less than 100 yards), I would not feel too bad about taking an elk with the .44 Mag if it meant survival by harvesting meat. "Back in the day" (early 1900s), my grandfather hunted deer, black bear and elk with a .30-30 to put meat on the table. Not that I would hunt elk with either gun on purpose, but if SHTF, I was hunting deer locally, and an elk presented a good "close range" shot, I would take it with either gun.