If you can, try to take Pops and his revolver out for a spin at a local range or friends farm, before the old timers passes away into memories. The time on the range and the ownership might mean a tad bit more if you have a shared living memory to go along with the both. Buy a box or two of ammo (or have parents or Poppop as you are underage for that). Be safe.
I agree, he could "gift" it to you now, via your parents for holding until you reach legal state age. Perhaps. Anyway, just one old mans thoughts. Might ask your parental units & Grandpa his thoughts to this idea.
S&W Revolver... Breaktop? I assume... which I know I should not do.
A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." - George Washington, January 8, 1790, First State of the Union Address