12 Mortars in One

[Parrott-Cannon]

Ed Hart built a mortar golf ball with three powder interchangeable powder chambers (cylindrical, trapezoidal, and elliptical), and 4 barrel bore lengths (zero, 4, 6, 8 inches).  I completed the initial tests today by measuring the velocity of golf balls shot with 60 grains of Schuetzen fg powder.  I made 5 measurements of the velocity for the 4 and 6 inch barrels.  The results are presented below:
 
4 inch bore length barrel          Average Velocity  89 fps          Standard deviation 14 fps
 
6 inch bore length barrel          Average Velocity  135 fps          Standard deviation 4.9 fps
 I have also conducted some preliminary test with a zero bore length - the golf ball sitting on the chamber.  The golf ball lifts of the chamber, the powder burns, and then the ball falls back to good old mother earth.  The golf ball remained suspended over the chamber until the powder burn was complete.

[Cannon Cocker]

Great stats.  I especially like the no barrel test which dispels the idea (which has been floating around here) that the chamber itself has some magical ability to launch projectiles all by itself. 

[Double D]

Ed Hart built a mortar golf ball with three powder interchangeable powder chambers (cylindrical, trapezoidal, and elliptical), and 4 barrel bore lengths (zero, 4, 6, 8 inches).  I completed the initial tests today by measuring the velocity of golf balls shot with 60 grains of Schuetzen fg powder.  I made 5 measurements of the velocity for the 4 and 6 inch barrels.  The results are presented below:
 
4 inch bore length barrel          Average Velocity  89 fps          Standard deviation 14 fps
 
6 inch bore length barrel          Average Velocity  135 fps          Standard deviation 4.9 fps
 I have also conducted some preliminary test with a zero bore length - the golf ball sitting on the chamber.  The golf ball lifts of the chamber, the powder burns, and then the ball falls back to good old mother earth.  The golf ball remained suspended over the chamber until the powder burn was complete.

Which chamber shape? .

Great stats.  I especially like the no barrel test which dispels the idea (which has been floating around here) that the chamber itself has some magical ability to launch projectiles all by itself.

Actually the  chamber can launch projectiles by itself.  We proved that by accident when we tested the chamber of my bowling ball mortar.   The greater the charge the further the ball traveled.

It was just more efficient to add a barrel and localized the blast effect and the ball went further.

[Parrott-Cannon]

Double D I like the videos.  Similar to what the golf ball did.  It obvious that the muzzle velocity is not created by the initial powder burn in the chamber.

[Double D]

Double D I like the videos.  Similar to what the golf ball did.  It obvious that the muzzle velocity is not created by the initial powder burn in the chamber.

Precisely!!!  Muzzle velocity, in layman and scientist terms is created by a focusing of expanding powder gases behind a projectile. 

[Parrott-Cannon]

Double D I like the videos.  Similar to what the golf ball did.  It obvious that the muzzle velocity is not created by the initial powder burn in the chamber.

Precisely!!!  Muzzle velocity, in layman and scientist terms is created by a focusing of expanding powder gases behind a projectile.

Keep in mind that the powder continues to burn when a barrel is inplace adding to the pressure and therefore the velocity.