THE EOYAL ARTILLERY INSTITUTION. 
263 
RESULTS OF EXPERIMENTS 
MADE TO TEST 
VARIOUS FORMS OF RIFLING. 
By JOHN ANDERSON, Esq. 
ASSISTANT SUPERINTENDENT, ROYAL GUN FACTORIES. 
For some time past a question has been frequently raised in regard to 
the tendency which different descriptions of rifling have to split the gun. 
The power required to give the rotatory motion to the projectile, through 
the agency of ribs or grooves in the gun, must necessarily cause an opposite 
straining in the gun tending to open it, or else to break the metal without 
actually splitting. 
We can easily perceive that an inclined surface is more apt to split the 
structure than a flat or perpendicular surface, but there were no precise data 
in regard to the position in which different planes stood with respect to each 
other. 
In order to ascertain this point, experiments have been made in the Royal 
Gun Factories, by preparing cylinders of cast-iron, all of equal strength and 
area; these ‘cylinders were bored and rifled on the several plans shewn on 
the accompanying table, and to prevent the risk of error from any excep¬ 
tional defect of any description, several of each sort have been experimented 
with. 
Into these rifled cylinders there were correctly fitted corresponding plugs 
of steel representing the projectile; these] plugs were made to fit the part 
representing the gun, and being of steel, which is a stronger metal than the 
cast-iron cylinders, it was resolved to continue the experiments until a form 
of rifling was arrived at, in which the steel plug would be broken before the 
cylinder was split open. 
The experiment consisted in fixing one end of the plug representing the 
projectile in a frame which was immovable, its other end being within the 
cylinder. The cylinder was fixed in the centre of a lever fulcrum, and 
capable of having a torsional motion given to it, by the application of 
weights on the extremity of the lever. 
The accompanying table shews the weight required to produce fracture on 
the several plans of rifling, and the diagrams will explain the exact form of 
the arrangement of rifling in the several systems. 
