RML 64-pounder 58 cwt


The RML 64-pounder 58 cwt guns were British rifled muzzle-loading guns converted from obsolete smoothbore 32-pounder 58 cwt guns.

Design

When Britain adopted rifled ordnance in the 1860s it still had large stocks of serviceable but now obsolete smoothbore guns. Gun barrels were expensive to manufacture, so the best and most recent models were selected for conversion to rifled guns, for use as second-line ordnance, using a technique designed by William Palliser. The Palliser conversion was based on what was accepted as a sound principle that the strongest material in the barrel construction should be innermost, and hence a new tube of stronger wrought iron was inserted in the old cast iron barrel, rather than attempting to reinforce the old barrel from the outside.
This gun was based on the cast-iron barrel of the Dundas Pattern 32-pounder 58 cwt gun, which previously fired a 32-pound solid shot. The gun was bored out to 10.5 inches and a new built-up wrought iron inner tube with inner diameter of 6.29 inches was inserted and fastened in place. The gun was then rifled with 3 grooves, with a uniform twist of 1 turn in 40 calibres, and proof fired. The proof firing also served to expand the new tube slightly and ensure a tight fit in the old iron tube.

Deployment

This nature of gun did see Naval Service with the Naval Forces of the Colony of Victoria in Australia aboard the ex Ship-of-the-Line Nelson. To maintain maximum capability the gunners aboard the Nelson were drilled for both Smooth Bore and Rifled ammunition, and so the guns retained the original Millar Pattern sights as well as having one set of R.M.L. sights placed to the right of the centre line - otherwise the sighting arrangement normally used in British service was a single set of R.M.L. sights on the centre line. The mountings used on this vessel were Wood Naval Standing Carriages.
The gun mountings for coast defence in both British and colonial locations varied enormously. Carriages in both wood and iron varied in complexity – from a simple wooden garrison carriage, traversing carriages, right through to some guns mounted on Moncrieff Disappearing gun carriages.
They became obsolete for coast artillery use in 1902, whereupon most of them were scrapped and disposed of.

Surviving examples