The WWII era railway gun the largest fired shot a round the size of a Buick and required two rail tracks to move.
Actually the largest rail gun was the "Schwerer Gustav" or large Gusav.
Used by the Nazis in WW2 and built by Krupps, it was a 31.5" or 800mm Bore.
Not the size of a buick. But probably the LONGEST gun built in that the projectile was shot from the muzzle using standard propellants, was for the HARP project in the 60's This started as a 16" 50 Caliber gun But was lengthened to 100 Calibers.
One caliber being the diameter of the barrel hence 1600" long or a bit over 133 feet.
This was a spare naval gun for the Iowa class battleship.
50 cal barret
i believe the 1st ever gun made was made from cast iron and was dated from the 13-15 century made by the Chinese
limosine limosine
A Lemo
Metropolis
The longest movie ever made was about 85 hours, "Cure for Insomnia".
Chau Chau
CHINESE
The first was the gatling gun invented in 1862
1974-'76 Cadillac Fleetwood was the longest in length.
Pants for the worlds tallest man.
I think it is 85. XPPP