Rules for Operating and Dismounting the Pratt & Whitney Improved Gardner Gun, As arranged by Captain John E. Greer, Ordnance Department, U.S.A.

To Dismount the Gun:

1) Unscrew the cascabel and raise the rear casing

2) Remove the barrels.  To do this, drive out the front and rear barrel-plate pins; interpose a plug of wood or a cartridge-shell between the rear of either barrel and its corresponding lock, taking care that it does not enter the chamber; turn the crank gently and the lock will force the barrels partly out of the casing, when they may be removed by hand.

3) Remove the locks, to do this, turn the crank until either lock-cam recoil-plate is uppermost; rotate the corresponding lock about the recoil-plate until it is vertical and draw it out at front.  The other lock may be removed in the same manner.

4) Remove the ejectors directly by their pins.

5) Remove the lock-cam, raising it vertically by means of its journal boxes.  The journal boxes may be removed from the cam by driving out the journal-box pin.

6) Drive out the lock-guide pin and remove the guide.  Te shell starters may be removed from the lock-guide by driving out their pins.

7) Turn out the cocking-cam screw, which enters the cam through the bottom of the casing, and remove the cam.

8) Remove feed-valve.  Drive out valve cap-pin, remove cap, pull out lever, lift out valve.

9) Drive out safety-crank pin and remove crank.  The safety-stop head, stop and spring may be removed from the crank by driving out the stop-head pin.

10) Drive out the safety-crank shaft and remove the spline.

11) Slide the main spring compressor out at the rear of the guide.  Drive out pins at rear and front.

12) Remove the mount and casing.

13) Draw back the lock-bolt from the socket of the bed-plate; unclamp the mount and lift it from the carriage.  The gun and mount may be removed directly from the carriage in the manner prescribed.

To assemble, proceed in the inverse order.

Note.--All taper pins in the casing are driven in from the right to left.

To Dismount the Lock:

1) Drive out the extractor-pin and remove the extractor.

2) Unscrew the lock head by means of the lock-wrench.

3) Uncock by pressing on the sear and turning cocking-lever to the rear; drive out the cocking-lever pin and remove the lever.

4) Draw out the firing-pin, remove the rack and unscrew the main-spring.

5) Drive out the sear-spring-pin and remove the spring.

6) Drive out the sear-pin and remove the sear.

7) Drive out the truck-pin and remove the truck.

To assemble, proceed in the inverse order, taking care to return the firing-pin so that its flat will be at the extractor-slot, and that the front tooth on the cocking-lever enters the front space in rack.