I took my kid hunting at age 10. He had a 243 Featherweight. His boot size was a six. The next year he complained that his boots hurt his feet. I took him to a sporting goods store and his foot measured 8 1/2. I wear a 9 1/2 so I asked the salesman to bring him a pair in that size. He wore them that afternoon and didn't hunt with me again until the following year, when his feet were a size 11 1/2.
Now he is even taller and larger. The little Winchester Featherweight is still a great rifle. Just had my first grandchild, a boy. Can't recycle the boots that were only worn once, but the rifle that has been used very little it still a prized possession. In about 10 years my grandson can sit in my lap and I'll wisper instructions into his ear. "Aim at the shoulder and sqeeze the trigger just like we practiced."
