What exactly is a .268 win mag?
Do you mean .264 Win mag?
If that's the case then yes the .264 Win mag is plenty enough gun for elk and even moose. Assuming, of course, you select a properly constructed bullet for hunting elk.
It will fire a 140 grain bullet at about 3100 fps. A 140 grain 6.5mm bullet has excelent ballistics in terms of BC and sectional density which, all other things being equal, means more retained long range velocity/ energy and more penetration.
You should have no problems what so ever hunting elk with a .264 win mag. Assuming you can shoot.

Of course going after elk is always a good excuse to buy another rifle if you want one.
