Hello

[Buffalobob]

Being as you plan to hunt elk, I would suggest that you stay with the 308 for two reasons. First - much better selection of factory bullets available for shooting elk, assuming you don’t reload.
Second- A little larger hole helps in making the bullet lethal.

Necking cases down and maintaining the same powder capacity generally means you are going to shoot lighter bullets faster at smaller animals. A good example of this is the 30-06 case which is necked down to a 270 Win and from there down to a 25-06. By the time you get it down to the 25-06 you have a very fast and lethal deer gun but not a very good elk gun
Just my opinion and I don’t shoot either of them

[Ludden_bd]

I am going to reload the bullets with my grumpy because he has allot of 7mm bullets and he said that he would help me with them I will be shooting 120 gr. BT's.

[Buffalobob]

The 120 Nosler Ballistic tip is not known for its ability to break through heavy elk bones nor would I shoot it at a deer. For deer I think you will find the 140 grain class of bullets will give good penetration. You will be better off with a 160 partition or Accubond for elk.

I shot a lot of 120 grain class of bullets at crows and groundhogs and they worked fine for that.

Just a suggestion is that if you want to shoot a 7mm maybe you might want to consider a 7WSM as it has a little more range and ability to shoot the heavier 7mm bullets.

[youarenotcrazy]

The 7mm-08 would be great for deer and probably fine for elk at the distance you specified, but you can sling a lot better bullets than 120's out of it with the right barrel twist. My savage loves anything 160 grains and up, and that is the size category you'll prolly want for elk. A savage with a 1-10" twist would be great, IMHO