RE: 30-30
The .270 is definitely NOT overkill. The three most commonly used deer cartridges are the .270, .30-06, and the .308. And as others have said, the .30-30 has more than enough power to kill these animals. As for ballistics, the .270, .30-06 and .308 are better. Although, Hornady I believe, has made a "soft tip" ballistic tip round for lever action rifles. The .30-30 does not kick as much also as an added bonus. Over all, there is nothing wrong with the .30-30, but you'll get more range and power with your relatives .270.