I was looking into one as well once and the way I see it is dont waist your time. I am a gun freak and I can tell you some balistics off my head 243 - 3000 fps with 100's out of mussle and roughly 1900 fps. A 6.5X55 swedish mauser is 2550 with 140's and has 2050 fps of pressure. The 243 is better and im not defending nothing because I have neither. It has the upper edge on distance and maintaing power. If I were you, for kids get em something like a 260 or 7mm-08 because they dont kick and at least you arent then still playing with glorified pop guns.