Grandson Lucas gets off the school bus at our house every day, due to the schedules and routes of the school bus. His dad meets him here, and we generally chat for a bit before he goes home. You never know what question he is going to ask. Lucas is 12 years old.
Lucas is a shooter in his school's rimfire team. His dad built him a Ruger 10/22 and from all reports, he is doing well with it. Today he wanted to know about bullet speed and RPM and barrel twist rates, so we went down that rabbit hole.
It still amazes me, and I know the match, about how fast a bullet spins when it comes out of the tube. The basic equation is here. He's a budding gear-head, so we had to relate that to engine rpm. He is amazed that a CCI mini-mag spins at lot faster than a small block Chevy.
Passing on the information. That's my job as a grandfather. I wonder what he is going to ask me about tomorrow?
I'd say the velocity of Sunlight is an upcoming question.
Can't wait til my Grandkids reach that age!
My dad learned more about volcanoes than he ever wanted to know when my daughter was perusing a couple National Geographics and started asking questions. He ended up checking books out of the library and then translating so a 4-year-old could understand. There were working models and samples of volcanic ash before her curiosity was satisfied.
You are my hero.
You are so very blessed to be able to spend such time with your grandkids! I know you appreciate it, too.
My wife and I both worked, hustle and bustle, much of that kind of time was missed.
We are both hopeful that plans and finances will allow us to help raise our grandkids as you are doing.
Next time twist rates come up, mention Greenhill’s and Miller’s formulas. Then mention that these are fine for stabilizing bullets flying in the air, but for hunting you want stability in a much denser medium, about 15% thicker than water. That way the bullet digs a straighter hole. This is always a faster twist than Greenhill gives. Then it gets complicated, as the bullet has to be strong enough to hold together in flight at that higher rpm, and tough enough to not over mushroom on impact, which makes it unbalanced which means it won’t penetrate straight any more. Long discussions can be had, science, physics, hunting ethics. One takeaway is that a larger caliber, fairly heavy bullet with round nose, thin jacket, fairly soft lead core, fast twist, moderate velocity is about the most effective hunting combo. Think .35 Remington with a 225-250 silver tip, but a 1:10 twist.
Learning about guns and ammo can lead to a lifetime interest in science and math.
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