My dad has one of the 16" rounds test fired out of the Navel ordinance factory in Pocatello Idaho. The 16" guns where designated 50 caliber/16" meaning 16" bore and the barrel is 50 times the length of the bore. The bullet weighs 2700 lbs. 96 lands each about 3/16 deep, it twists twice in its 66 foot long barrel launching the ton and a half projectile up to 42,000 yards

The interesting thing is, concerning pistol-rifle-artillery, our pistol man Elmer Keith graduated (no pun) to artillery, pioneering duplex loads and tube ignition that are used to this day. Sure carried a handgun though.

So how do you get one of these? Well it was pretty simple back in the day. You looked for the 20 foot crater in the foot hills outside of town and you dug till you hit metal. They guy my dad got this one from dug up three, the other two are the posts for his front gate.

So... MOA at 42,000 yards is a bit bigger than a half mile circle? Around 3500 feet if I did my math right.

Not as cool as a Naval gun but you can actually shoot it with us !! 76mm pushing a 12lbs AP bullet out of a 18 ' barrel @4200fps

I think we are both wrong. 1"@ 100 yards so 4200" @ 42,000 yards so 350 feet, I had one too many zeros in my head