.308 was created and beats 30-06 in terms of size and weight, cause the case is smaller, less volume to carry the same amount of rounds, and with modern powder can push a standard round the same velocity. Neat little package for the military, making it possible for soldiers to have more rounds on them or less weight. Well, does this apply to sporter applications and hunting? mmm.. not really. .308 should work fine for deer, very popular cartridge and I hear gets a bit better accuracy shooting long distance. 30-06 with its larger case, from my understanding provides more flexibility and options for hand loading. You can make light loads and plinking rounds, but because the case is larger, you can push a heavier bullet faster than .308 .... so, and I don't really hunt so, for what it is worth, I have my Dad's 30-06 deer rifle, and I'm glad it is that cartridge. I guess I'm a traditionalist and there are newer good cartrdiges, but for general hunting applications, I don't think any are outstanding or superior to the old 30-06 in a way that would make me replace a 30-06 with something firing a newer or military NATO cartridge.
put it this way, I bet sometime in 1920, or 1930, someone was asking the same question as you back then. Here we are several generations later - and 30-06 is still one of the top cartridges, so unless there is some advancement or new technology replaces a lot of things, 30-06 IMHO will be around for at least several more generations.
