17. TO PREPARE TO FIRE. Crew being at dismounted posts, hatches open. The antiaircraft gun is uncovered and half loaded as the tactical situation dictates.

Tank Commander	Gunner	Bow Gunner	Driver	Cannoneer
Command: PREPARE TO FIRE.
Clean gunner's, loader's and sergeant's periscopes, gun telescope and cupola vision blocks.	Unlock traveling lock; elevate howitzer.	Lower seat. Release traveling lock.	Lower seat. Clean periscopes.	Inspect bore and chamber of howitzer.1
	Check traversing and elevating mechanisms. Check firing controls (including solenoids).	Half load bow gun. Clean periscopes. Check ammunition. Close hatch; raise periscope.	Close hatch; raise periscope.	Half load co-axial machine gun. Inspect smoke mortar; load mortar. Open floor compartment.
Check vane sight.	Check periscope and sights.2			Check 105-mm rounds, smoke bombs, and machine gun ammunition.
Close hatch if desired.	Uncover and check elevation quadrant and azimuth indicator.
Command: REPORT.	Report "Gunner ready".	Report "Bog ready".	Report "Driver ready".	Report "Loader ready".

18. DUTIES IN FIRING.

Tank Commander	Gunner	Bow Gunner	Driver	Cannoneer
Give fire orders (FM 17-12). Turn on exhaust fan.		Fire on designated targets and on emergency targets that appear.	Turn on ventilating blower if not already operating.	Load type ammunition indicated in fire order (inspect each round).
Observe and sense each round and notify gunner of changes in range or deflection.	Fire on targets designated. Observe and sense all rounds through sights.	When not firing, observe in assigned sector.	Observe in assigned sector and be prepared to move tank as ordered.	Signal READY each time piece is loaded by tapping gunner on left leg.
Control driver with interphone.	Continue to fire as directed.			Reload all turret weapons. See that all fuzes are at DELAY unless ordered otherwise.
	Call MISFIRE if piece fails to fire.			In case of misfire, check that breech is closed, piece in battery; recock piece and signal READY to gunner.
	Call STOPPAGE if coaxial gun fails to fire.			Reduce stoppages in coaxial machine gun.
	Tell loader when to fire coaxial gun if solenoid fails to operate.			Fire coaxial gun by hand when directed by gunner.
Fire AA gun.				Fire AA gun.
Determine when mortar smoke screen should be laid and give commands to produce the desired effect.	Rotate turret as directed by sergeant in adjusting smoke screen.			Keep mortar loaded at all times; adjust range, and fire immediately on command of sergeant.
When ordered by platoon commander, adjust indirect fire from forward position.	In indirect fire: Lay piece for direction. Lay piece for elevation. Set off deflection.			Keep record of ammunition expended for entry in gun book by platoon leader (number of rounds each type).
Indicate aiming point to gunner.	Fire piece on command. Make designated corrections in deflection and elevation.
				Inform sergeant when ammunition needs to be re-stowed.
	During lulls in normal activity observe in assigned sector.			During lulls in normal activity observe in assigned sector.

19. TO SECURE GUNS.³ In battle this operation is normally followed by RE-STOW AMMUNITION.

Tank Commander	Gunner	Bow Gunner	Driver	Cannoneer
Command: (CEASE FIRING) SECURE GUNS.
Open hatch. Raise and mount convoy seat.	Turn off firing switch. Lock howitzer in travel position.4 Lock turret lock.4	Clear bow machine gun; engage traveling lock. Lower periscope. Open hatch (first check position of howitzer). Raise seat to convoy position.	Lower periscope. Open hatch (first check position of howitzer). Raise seat to convoy position.	Clear coaxial machine gun. Clear howitzer; inspect bore and close breech. Clear smoke mortar. Open hatch.
Command: REPORT.	Report "Gunner ready".	Report "Bog ready".	Report "Driver ready".	Report "Loader ready".

20. TO LOAD ALL WEAPONS. The howitzer is loaded on order. This is normally the fire order, but some types of action will dictate loading prior to the appearance of a target. Machine guns are clear until the command PREPARE TO FIRE, when they are half loaded. When the fire order is given, however, or if the unit is deployed for combat, all machine guns will be fully loaded. This does not necessarily apply to the antiaircraft gun, which is uncovered and half loaded as the tactical situation dictates.

21. USE OF AMMUNITION. a. The order of withdrawing ammunition from its stowage space in the tank is based on the principle that some readily accessible rounds always will be saved for emergency use. Other crew members will pass ammunition to the cannoneer if necessary to prevent his having to use these rounds. During combat, the position of the turret will affect the accessibility of the ammunition in various parts of the tank. In drill, however, to establish a sound method from which commanders may deviate as the need arises, the following procedure should be adhered to:

b. Ammunition is taken from its stowage space in the tank in the order: (1) Three front rows left of power tunnel; (2) racks beside bow gunner in right sponson; (3) top racks behind bow gunner. The two rear rows left of the power tunnel will be saved as a reserve for action where speed of loading is of the utmost importance. As time permits, or on the command RE-STOW AMMUNITION, rounds are moved from the racks beside the gunner in the right sponson and from the bottom racks behind the bow gunner to those which have been emptied in firing.

c. Upon completion of re-stowing, reports are given on the number of rounds remaining. For example the bow gunner reports, "Three smoke, six HE remaining in forward racks right sponson; one-two HE remaining right of power tunnel". The gunner reports, "Rear racks right sponson empty". The cannoneer reports, "Three smoke, three HEAT, one-nine HE remaining left of power tunnel".

22. TO LOAD AMMUNITION. Ammunition for the howitzer will be crimped upon assembly and should then be loaded and stowed with great care to avoid striking the fuze end or the primer on a hard surface, burring the rotating band, or denting the case. (See TM 9-1900.) If time is available, each crimped round should be tried in the piece before stowing to see that it can be loaded. If for some reason rounds can not be crimped, each case should be tried in the piece prior to assembly of the round. All rounds of HE will be set at FUZE DELAY at this time. Both howitzer and machine gun ammunition will be passed through the hatches as most convenient under the circumstances, a man being stationed on the forward or rear hull to relay it to those in the tank.