Subdjoe,
I think every gun was issued a worm, and it was carried on the gun's carriage. Artillery Drill, G. W. Patten, see p. 52, Dismounting Pieces, and also read the excerpt from the West Point instruction book, No. 199.
Navygunner and Subdjoe are right; it would appear that the worm wasn't used at all in servicing the bore when firing the piece. Read the West Point instruction book, and Benton's stated use for the worm. P.252. Another thing that's surprising, is that no dry sponging is mentioned; or are they only discussing dry sponging?
A course of instruction in ordnance and gunnery
By James Gilchrist Benton, United States Military Academy
Cadet Ordnance Instruction BookChapter IX. Loading, Pointing and Discharging Firearms.
435. Precautions. After a piece has been discharged the bore should be well sponged, to extinguish any burning fragments of the cartridge that may remain; and to prevent the current of air from fanning any burning fragments that may collect in the vent, it should be kept firmly closed with a thumb stall in the operation of sponging. Experience shows that the use of a wet sponge is dangerous, as it contributes to form, from the fragments of the cartridge bag, a substance which retains fire.
P. 252, 4th. The worm (fig 74), is a species of double corkscrew, (2), attached to a staff, and is used in field and siege cannon to withdraw a cartridge.
199. Gun-carriages. Field carriages are characterized by great lightness, strength, and mobility. They are The 6-pdr. gun and 12-pdr. howitzer carriage. The 12-pdr. gun (light) and the 24-pdr. howitzer carriage. The 12-pdr. gun (heavy) and the 32-pdr. howitzer carriage.* These carriages are of similar construction, the only difference being in the size and strength of the several parts. The first is mounted on light, or No 1 wheels, and the second and third on No 2, or heavy wheels. Attached to each carriage are the following named implements, viz., two rammers and sponges, two trail handspikes,
one worm, one sponge bucket, one tar bucket ,one watering bucket.
*The 10-pdr. Parrott and the 3-in. rifle guns are mounted on the 6-pdr. carriage, and the 20-pdr. Parrott rifle-gun is mounted on the 12-pdr. (heavy)carriage.