Ordnance cast of gun metal are generally designated Brass Ordnance.
Brass guns are used for field batteries, they having been considered preferable to iron for the service, being lighter than iron guns could be cast of the same calibre, without risking their bursting.
Brass guns are, however, soon rendered unserviceable by repeated and quick firing.
Iron guns are better adapted for batteries in the attack or defence of towns or fortresses, and also for service on board ship; being less expensive than brass, and better able to sustain long-continued and rapid firing. At the siege of Badajoz the firing continued for 104 hours, and the number of rounds fired from each 24-pounder averaged 1249; at the siege of St. Sebastian, each piece fired about 350 rounds in 15½ hours. None of these guns were rendered unserviceable; but three times the number of brass guns would have been required to produce the same effect, or maintain such long and rapid firing.
Service Charges of powder.
| For heavy guns | ⅓ the weight of the shot. |
| For light do. | ¼ do. do. |
The Point blank range of Iron 32, 24, 18, and 12-pounders with solid shot varies from 380 to 260 yards; from which to 1200 yards, every ¼ degree increases the range about 100 yards; and from 1200 to 1500 yards, every ¼ degree increases the range about 50 yards.
The Point blank range of Brass, Medium 12, 9, and Heavy 6-pounders, with solid shot, is 300 yards, and from which to 700 yards, every ¼ degree elevation increases the range 100 yards; from 700 to 1000, every ¼ degree increases it 75 yards, and from 1000 to 1200, every ¼ degree increases it 50 yards.
The Point blank range of Brass, Light 12, 6, and 3-pounders is 200 yards, from which to 600 yards, each ¼ degree increases the range 100 yards, and from 600 to 1000, each ¼ degree increases it 50 yards.
Note.—For Weights, Dimensions, Ranges, Charges, &c., vide [Tables.]