A 30/30 AI should work fine for deer and you can expect maybe 100 to 200 fps more velocity from it than from the regular old 30/30. If you get an Encore, you have a bunch more calibers with greater velocity to choose from like the 7mm/08, 308 Win., 30/06 and many more.
You didn't mention what ranges you anticipate shooting deer at, whether you reload, etc. which all enter into the equation of what caliber you choose. If you don't reload, there would be no advantage to the 30/30 AI. You could shoot regular 30/30 ammo it it but then what is the point of having it. The 30/30 case is not as robust and will not take as many reloadings as a 7mm/08 case if that makes a difference. The 7mm/08 has more accuracy potential as well.
