Rifled muzzle loaders were quite successful. To fire conical shot from Rifled Muzzle Loaders (RML), a number of strategies were used, such as fitting lugs onto the shell that engaged in deep rifling groves cut into the barrel. Another weakness of Armstrong guns was that there was nothing to prevent the gun being fired before the breech was closed. This prompted the RN to reverting back to muzzle loading (ML) guns for the larger pieces. On a number of occasions the vent pieces were blown from the guns. During the bombardment of Kagoshima (Japan) in 1863 there were 28 accidents in the 365 rounds fired from 21 guns. However a conical shot, will tumble unless it is rotating about its longitudinal axis and hence must be fired from a rifled barrel.Īrmstrong guns were fitted widely in the RN, but they suffered a number of design weaknesses. The need for a gun capable of throwing a shot with sufficient momentum to pierce the armour plate being fitted to the warships of that time, a trend started by the French in La Gloire, (1853) requires either a very large spherical shot (such as the Rodman 16 inch smooth bore muzzle loader used on Monitors during the American civil war) or an elongated shot – such as we are familiar today. Rifled Breech Loading (RBL) guns, after the Armstrong design, were introduced in the 1850’s, and many examples can be seen in HMS Warrior.

The 12 inch guns fitted in HMS Dreadnought (1906) were the result of 20 years of development in breech loading (BL) main armament in the Royal Navy.

Hms dreadnought 1906 download