3.6.-INCH B. L. RIFLE, MODEL 1891 (REVISED).
| Material | steel |
| Total length | 7.79 feet |
| Calibre | 3.6 inches |
| Weight | 1181 pounds |
| Grooves | 26 |
| Twist of rifling | 1 turn in 50 to |
| 1 turn in 25 calibers | |
| Axis of trunnions above ground | 3.56 feet |
| Powder-chamber | cylindrical |
| Vent | axial |
| Preponderance | 31 pounds |
| Muzzle velocity | 1550 ft.-sec. |
| Maximum range for shrapnel | 7420 yards |
Fig. 49.
This gun is similar in construction to the 3.2-inch (revised November 11, 1892).
Nomenclature.—ab, locking-shoulder and recess; c, conical gas-check seat; d, cylindrical powder-chamber; e, connecting slope for seat of rotary band; f, slope from no lands to maximum lands.
SIGHTS.
Similar to those of 3.2-inch gun.
AMMUNITION AND FUZES.
The ammunition differs only in weight and dimensions from that described for the 3.2-inch gun. Fuzes are the same.
| Powder-charge | 4.1875 pounds U. F. sphero-hex. |
| Weight of shell, filled | 20 pounds |
| Bursting-charge, shell | 14½ ounces |
| Weight of shrapnel, complete | 20 pounds |
| Bursting-charge, shrapnel | 4 ounces |
| Total number of balls | 218 |
| Total number of individual pieces | 280 |
CARRIAGES, LIMBERS, CAISSONS, COMBINED BATTERY-WAGON AND FORGE, ARTILLERY-WAGON.
The carriage for this gun weighs 1300 pounds. The first 25 carriages were made with the double-screw elevating device, and the second 25 with the first form of lazy-tongs, and were intended for the 3.2-inch gun. They have been changed for 3.6-inch guns by cutting out the upper-front transom under the trunnion beds leaving only enough metal on each side to hold the eyebolts of the forked radial bar for the elevating device, and cap squares with eyebolts have been substituted for the old cap squares with chin and eyebolts. The double-screw elevating device on the 25 carriages now having them are retained; but all others will have a form of lazy-tongs, operated by bevel gears and a crank handle at the side, like that of the double screw; otherwise the carriage is similar to that of the 3.2-inch gun already described. The limber-chests will probably be fitted for 36 rounds of ammunition; which is the only difference between limbers, caissons, etc., used with 3.2-inch and 3.6-inch guns.
HARNESS, ETC.
See [page 150] et seq.