Fig. 13.
DESCRIPTION.
| Material | steel |
| Total length | 3.76 feet |
| Length of bore | 3.25 " |
| Travel of projectile | 3.02 " |
| Calibre | 3 inches |
| Weight | 216 pounds |
| Grooves | 24 |
| Twist of rifling, uniform | 1 in 25.59 cals. |
| Muzzle-velocity | 870 f. s. |
| Maximum range | 4000 yards |
The breech-mechanism of this gun differs from the 1.65-inch in that its stop-bolt engages in a guide in the lower part of the block.
The front sight is of the open type, allowing of a large field of view. The tangent-sight is provided with a sliding head by means of which it may be set before placing it on the gun, and a deflection-slide for correcting for drift, wind, etc. On the deflection-slide is an open notch for rough, and a peep-sight for fine, sighting. The sight-bar is graduated on one side in ranges, on the other in millimetres. The sights are on the left side.
The Carriage.
Fig. 14.
Nomenclature.—(1) trail; (2) axle; (3) wheel; (4) cap-squares; (5) hooks; (6) elevating-screw; (7) elevating-lever; (8) elevating-transom; (9) lunette; (10) lunette-plate; (11) trail-handles; (12) brakes; (13) sponge and rod.