When I was a young hunter, just learning to hunt and shoot, one of my "mentors" was an older neighbor who was consistently one of the best deer killers I ever knew.
He hunted almost exclusively with a Winchester 94 in .32 Special. Although he owned a number of different guns (one of the main reasons I was fascinated with him...as I was a "gun nut" even at 10 years old) he always seemed to pick up that .32 Special when it was time to make meat.
Even in the 1960's the .32 Special had a reputation of being less accurate than the .30-30, but my friend insisted this was untrue. He didn't shoot targets, but could shoot gumballs from a tree time after time to prove his point.
He also insisted that the .32 was a more effective killer than the .30-30 and this was the reason he chose that chambering. Although the magazines I read stated that this was untrue, it was hard to argue with his success over the years.....and he had used both chamberings enough to "know".
I eventually owned and used the .30-30 and .32 Special myself and though a "sample" of 10-12 deer killed with each may not be large enough to prove anything, the .32 DID seem to me to hit a bit harder and kill quicker than the .30-30. Not a big difference, but enough for me to notice.
