The 30 Winchester commonly known as the 30-30 is a low powered bush round. If you are within 100-125 yards and you know the bullet drop for your particular round and gun, you should easily be able to take down an elk with a well placed shot. Like any other gun you need to know it's limitations, but I know of many hunters who have taken down bull elks with their trusty 30-30. nady makes a lever revolution round that will increase your range on a deer from 150m to 200m and depending on your gun and barrel length you will learn what your max effective range, but i wouldn't go any further than about 220 even on a deer. As with all guns and ammo, know it's limitations and you should be fine. I suggest setting up targets every 50-100 yards for 400 yards, if you have the space this. I you can hit a 2-3 inch square consistantly at 100-150 yards then I trust you would be able to easily take down an elk at 100 yards with a well placed shot behind the shoulders. Remember that the bullet you use is extremely important, make sure you have the right grain and in situations like this, get premium bullets for larger game.