The Manufacture of a Rifle.

Auckland Star, Volume XXXVII, Issue 164, 11 July 1906, Page 2

The Manufacture of a Rifle.

The Royal Small Arms Factory is, perhaps, one of the largest places of its kind in England. Six large buildings, literally teeming with machinery, constitute the factory and repairing department. The visitor is bewildered by the multiplicity of machines, all actuated from one source, and the miles upon miles of belting which work the lathes, at which the different parts of the rifle are made. The steel body of the rifle itself, which, starting on its eventful career in the smithy, is at last hardened by being dipped in a bath of oil, goes through 150 operations alone. It is the barrel maßing which has the greatest fascination for a visitor. He sees lying in heaps long rough bar 3of steel, which, after an exceedingly eventful journey through the different parts of the workshop, finally make their appearance -as the long blue-looking rifle barrels, which will, perhaps, be responsibe for the destruction of many scores of human lives. The cylinders of rolled steel are purchased of the contractors in short lengths, and the chief work of the smiths consists in heating and lengthening them. The change to tne finished article is, ol course, very gradual. After being lengthened in the smithy, these barrels are bored, and for this purpose are fixed in a lathe and drilled from each end of the bar. They are now approximately near the required gauge for rifting, and any further metal is removed by means of emery and water. Following this, a very delicate test is applied. The operator holds the barrel in an upright position, closes the lower end, and then places a cylindrical piece of metal inside the top end, which the compressed air in the tube should support. On removing the top, or plug, the gauge should at once drop through. The size of bore being satisfactory, the next Lest of the barrel is for straightness, and this test is always applied prior to rifling the bore. The barrel is held at an angle and supported by a stand, which enables the man to see the light reflected through it in perfect rings, provided the bore is absolutely straight. But the "viewer's" subsequent test is more critical still, and is so trustworthy, that in a total length of 30.197 in he is able to judge of a deflection of 1000 th of an inch by causing the barrel to rotate in a lathe furnished with a dial indicator at the end. This dial is bo finely marked that it can only be read by the aid of a magnifying glass. In a barrel so tested, which was the 4000 th of an inch out, two smart blows with a hammer on the right spot completely straightened it. Now the rifler takes the barrel under his special care. He uses what is undoubtedly the most intricate and yet most perfect piece of machinery in the place; The depth of rifling is only .005 of an inch, and there are seven grooves, which the cutting tool produces after traversing the barrel 42 times, or six times for each groove. The barrel remains fixed in the lathe, whilst the cutting tool worms its way through it, making one complete turn in every 10in, and removing each time but a veiy small amount of metal, yet extracting it in one unbroken piece, in appearance like a spiral spring. It is the backward movement of the cutting tool that rifles. When six cuttings have made one groove of the necessary depth the barrel is turned in the lathe one-seventh of its diameter, and so on in succession till the whole seven grooves are formed. It is now "rifled." Then the barrel goes to the proving house, and when passed goes on to a room where all the component parts are assembled.