Re: 308win load for 15 yr girl
If all you can get is Horn, speer and sierra, I would look at the hornaday interbond. the 165 will recoil a bit less than the 180's.
If you have access to 150 ACCUBONDS and Hodgdon BENCHMARK I would highly recomend that load assuming you keep the range to what you mentioned. I have seen 1st hand what the 150 AB will do to a bull moose which is bigger than an elk. The velocity was only 2800 FPS to boot. The recoil was very very mild. The accuracy was fantastic. All things concidered, (mild recoil, accuracy, and terminal performance of the bullet) it would make a suitable load for elk for a young female hunter at the ranges in question. Sure there are 'better' loads for elk but all things concidered such as the hunter and ranges used, the 150 AB is a hard load to beat. This is the load I will be using for my wife to harvest a caribou next year for the same reasons. The shots will be close and she is sensitive to firing a rifle and the load is extremely effective.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.