Geoff: this pic is on the thread I linked

[Linked Image from photos.smugmug.com]

The box is weighted with 25# and the bungie cords secure the barrels but allow me to rotate the barrels while measuring to find the MWT; usually the 3:00 position.

My gauge has a measuring tape affixed so I know exactly where I am

[Linked Image from photos.smugmug.com]

An assistant (the fella with the barrel) records the numbers here

[Linked Image from photos.smugmug.com]