Great story. Great Dad. Great son. Great rifle. The picture of your Dad and the rifle says it all. A great Christmas.
I know how you feel. My brother and I gave my Dad a Marlin 39a lever action 22 LR years ago. He gave my brother and I Marlin 39a rifles when we were 13. We returned the favor and gave him one. He said the same thing... "No one has ever bought I rifle for me." He was 65 years old. He couldn't wait to get it outside to get into a plinking session with us. A memory that will last forever.
It IS better to give than receive. Well done.
Here's a link to an interesting study of 35 Remington bullet tests (expansion). Cut to the chase, the Remington 200 grain jacketed round nose works great.
35 Remington bullet tests I had two Marlin 336's in 35 Rem (an early waffle top 336A ballard rifled model, and a 336c 20" microgrove version). I'm still trying to figure out why I sold them.
