So I have a friend that seems to have this obsession with long range shooting, and I thought I may help facilitate her habit and augment my rifle collection at the same time. I'm somewhat interested in long range shooting, but I was also considering getting into deer hunting. What I'm looking for is a flat-trajectory, Texas Whitetail-capable round that isn't horribly expensive and doesn't have too much recoil (my friend is recoil sensitive, but she can handle a 12 ga pump with light target loads). If I were just going to do the longrange shooting I would probably choose a gun in .223 because of the ammo cost but since I've added the deer gun qualifier I'm thinking something more in the range of .243. So, my question is, what would you consider to be the cheapest cartridge that still has a fairly flat trajectory out to, say, 300 yards, can kill a whitetail with good shot placement at maybe 200 yards tops, and isn't a shoulder-killer? I'm currently thinking .243, but am open to suggestions. Also, if anyone could recommend a platform I'd appreciate it. I'm currently looking into the NEF/H&R single-shots. Thank you!