The 243 is a fine caliber for a young person to start out with, heck i know guys who use a 243 all the time now. The 25.06 is also fine caliber for a youngster but does have more recoil than a 243 just depends on the bullet weight and load in general if handloading. In my experience a 25.06 loaded with a 120grn bullet and a full case of powder packs a pretty good punch probably as much as a 270 imo. The same gun with a 100grn bullet and a lighter load will kick less. My son killed his first deer with a 243 and a 100grn bullet at the age of 11 and used that rifle for several years. He' s now 13 and uses a 25.06 and even shoots a 30.06 from time to time loaded with a 130grn bullet so i think bullet weight does make a difference.