Navies of the world

by Edward W. Very

The grooves of the breech-loader (original) are saw-toothed in shape, vanishing at the shot-chamber for use with a lead-coated projectile.

Armstrong Groove for Breech-Loader.

Armstrong Shunt Groove for Muzzle-Loaders.

Armstrong 100-ton Gun (Improved Construction).

The grooves of the muzzle-loader (original) are of the shunt or double type, being cut to the full depth for the entire length and one half the width of the groove. The other half of the width is cut on an incline from the muzzle towards the chamber, this half being the driving side. The loading edge of the groove near the bottom is cut at a sharp angle so as to throw the studs of the projectile against the driving edges of the groove, and give it a close bearing. In coming out the studs ride up the incline of the driving side and are pinched, centring the projectile. This groove is now obsolete. The groove of the improved muzzle and breech-loaders is the plain groove.

BREECH-LOADING GUNS
(ORIGINAL).

7-inch B. L. R. 82 cwt.