Will never happen...one rifle for a lifetime. Show me just one guy who hangs here who has done that, just one.
No kidding, but it is nice to dream.
I didn't take the OP's question to mean that he expected to buy a rifle that would be the ONE rifle for a lifetime, just A rifle that would last a lifetime.
I still have a walnut/blue 12ga BPS shotgun that was the first gun given to me by my parents, and it's still in excellent condition. If it had been a cheap synthetic Mossberg, I might have sold or traded it in my younger days. Now that I'm old enough to appreciate it more for sentimental reasons it will never be sold, and I have many other shotguns. There's something about that first one, and it should be a nice enough one that the child will want to hang on to it.
