312 



THE SPORTING EIFLE. 



THE METHOD OF RIFLING. 



There are several 'machines by which the spiral grooves may 

 be cut in the interior of a barrel, but all proceed upon the 

 principle that a cutter of the shape of the groove is passed 

 backwards and forwards in a spiral manner through it, the 

 barrel itself being fixed. The annexed engravings show one 

 of the best and most simple plans adopted by Messrs. Prince 

 and Green in London, and by Mr. Rigby in Dublin. Fig. 66 



RIFLING MACHINE. 



represents a strong iron table upon which are fixed two 

 slotted frames. One of these a has two sliding vices tra- 

 velling on it, and capable of firmly securing the barrel b 

 ready for the cutter c. This is attached to a rod which 

 passes through a square hole in the plate d, and is driven 

 backwards and forwards in a perfectly straight line by the 

 rollers working in the two slots e e. The strong rod /, 

 figs. 66 and 67, is made to work backwards and forwards by 

 the wheel shown in fig. 67, the horizontal line being pre- 

 served by the slots e e, fig. 66, and the hole in the centre 

 of the plate d. Here, then, we have a very simple plan for 

 producing a steady yet powerful horizontal motion for the 

 rod which carries the cutter, and which in the ordinary way 



