RE: Caliber for son's first deer rifle?
I started shooting a 25-06 at 10yrs old. I still have one and still love it. It wont kick any harder than most 243's and has alot or range and great power for deer. I recommend a 25-06 for anyone getting started with hunting. Another great round for starters is a 7mm-08.
The 6.5x55 and 260 are cool and all that, but try to find a rifle chambered for either or a wide bullet selection in factory loads. If you reload and have an old rifle chambered for either caliber theyre great. But for now, stick with what you can find chambered in any rifle made today and find any type of ammo desired. the 25-06 or 7mm-08