I recently ran across an article about the Confederate Williams cannon- here's a little bit about it: The Williams gun was actually a crank operated, very light artillery piece that fired a one-pound (1.57-caliber) projectile with a range of 2,000 yards. A crew of three men was required to operate the weapon, which was said to be able to fire 65 rounds a minute.
The major problem with this otherwise successful gun was overheating. When rapid fired, the excessive heat made the breech jam due to metal expansion
Well suited for cavalry operations, the Williams gun had a four foot long barrel and was mounted on a two wheel carriage. The gun was pulled by one horse. R.S. Williams himself was made a Captain and given a six gun battery of his invention that was attached to and saw service with Gen. George Pickett's division.
The weapon gave good service with the 4th Kentucky cavalry in the action at Blue Springs, Tenn., in October 1863. Ten Williams guns with all their accessories were captured at Danville. Va., in 1865.

The article said that this battery was attached to Pickett's division- however, a somewhat cursory examination of the orders of battle for Gettysburg and the battles with Grant do not confirm this statement. As Pickett's division was in NC during Longstreet's trip to the Western Theatre- I assume the 6 gun battery was detached and went with Longstreet's men to Tennessee- but they must have come back if they surrendered at Danville- has anyone run across Capt RS Williams and his battery of rapid firing cannon?-Thanks-Barrett