Any one that wants to debate whether or not a 30-30 is adequate for deer is just not being practical.
I prefer a Marlin 1894 in 44 mag, but the 30-30 works just fine.
.357 works well for Southern Whitetails also. The savy hunter using one of these three, keeps his shots under 75 yards, practices his woodscraft as much as his marksmanship, and has a good understanding of Whitetail anatomy.
My son's GF takes deer year after year on her farm in North Fla, using a .357 Rossi Model 92, and my handloads. She hunts in the swamp, takes short distance shots, and is deadly accurate.