Note.—All projectiles will be service weight and form, cast iron only, or such projectiles as are specially designated for target practice. Companies which cannot have subcaliber practice at home station have only one-half the annual subcaliber allowance.
12-inch Mortars.—The number of zones, muzzle velocities corresponding thereto, zone limits, width of zones and overlaps for the 12-inch mortar, cast-iron, steel-hooped, and the 12-inch mortar, steel, have been rearranged and are now as shown by the following table:
| Column headings: | ||||||||||
| A = Number of Zone. | ||||||||||
| B = Muzzle Velocity. | ||||||||||
| C = Weight of Projectile. | ||||||||||
| D = Zone Limits. | ||||||||||
| E = Width of Zone. | ||||||||||
| F = Overlaps. | ||||||||||
| 12-inch Mortar, Cast-iron, Steel-hooped. | 12-inch Mortar, Steel. | |||||||||
| A | B | C | D | E | F | B | C | D | E | F |
| F. S. | Lbs. | Yds. | Yds. | Yds. | F. S. | Lbs. | Yds. | Yds. | Yds. | |
| 1 | 560 | 1046 | 2225-3000 | 775 | 400 | 550 | 1046 | 2210-2970 | 760 | 370 |
| 2 | 610 | 1046 | 2600-3480 | 880 | 480 | 600 | 1046 | 2600-3431 | 831 | 361 |
| 3 | 670 | 1046 | 3080-4110 | 1030 | 400 | 660 | 1046 | 3070-4030 | 960 | 399 |
| 4 | 743 | 1046 | 3710-5000 | 1290 | 400 | 725 | 1046 | 3631-4800 | 1169 | 371 |
| 5 | 837 | 1046 | 4600-6240 | 1640 | 400 | 810 | 1046 | 4429-5940 | 1511 | 420 |
| 6 | 910 | 1046 | 5840-7319 | 1479 | 594 | 915 | 1046 | 5520-7476 | 1956 | 449 |
| 7 | 1050 | 824 | —— | —— | —— | 1050 | 1046 | 7027-9250 | 2223 | 492 |
| 8 | —— | —— | —— | —— | —— | 1300 | 824 | |||
Note.—Each smokeless powder cartridge to have 10-ounce igniter (black rifle powder) at each end in addition to above charges.
All smokeless-powder charges for mortars will be issued made up, ready for use, as the charges vary with each lot of powder. They will be distinctly marked to indicate the zone number.
(a) SERVICE OF THE PIECE.
Q. Give the general duties of a gun commander.
A. The gun commander repeats the commands "Commence firing" and "Cease firing," announces the kind of projectile to be used, the order to fire, the method of pointing, and in restricted fire the number of shots and the firing interval, all in accordance with the orders of a battery commander. The gun commander is responsible to the battery commander for the condition of the material and the efficiency of the personnel of his command.
Q. Give the general duties of a chief of detachment.