Just remember one thing! Their have been more deer taken down with 3030 then any other rifle.
That would be pretty gol-dang hard to prove and I personally doubt it. The .30-06 has been around almost as long as the .30-30 and has out ranked it in yearly ammunition sales since it first displaced the .30-30 from that position back in the 1960's.
But, the 30-06 is so fast that most of the time, the bullet just zips through before it can expand...
I agree, the '06 would be close competition, but the good ol' .30-30 has certainly taken it's share. On a personal note, I have killed more with a .30-30 than anything else, but that's me.
