A short defense of the .30 Carbine round:

As DeGuello pointed out, bullet placement is everything and I would start with that as a given with regards to any shot fired with any round. Secondary to placement may be bullet construction, full metal jacket vs soft point vs SJ Hollow point, and so on.

My first 25 years hunting were in woods and swamps in Tennessee, Arkansas and Mississippi. I never encountered a deer over 100 yards away while hunting, most 25-50. I think there is an ENORMOUS difference between an unexpected (to them at least) shot on a subject, two legged or four at 50 yards and a "Hail Mary" shot with FMJ rounds at 200-300 yards at a charging Communist wearing 2-3 inches of heavy winter clothing and web gear as was the case in Korea, thinking specifically of Chosin in '50.

Know your subject, (agitated or not, heavily clothed, muscled, furred) , know your round, place your shots.

While not a great round or the "best" round whatever that may be, I think the .30 carbine is under appreciated for what it can do and is a fine entry caliber for the kind of shooting I have seen and described above.