RECOIL. I87 



retraction or unevenness, however small, which throws 

 back the gases while the powder is burning, and thus 

 makes the gun kick, instead of discharging evenly and 

 without extra friction, as in a perfect cylinder. Any slight 

 substance adhering to the inside of the barrel, or the 

 fact that one part of the barrel is thicker than another, 

 diminishing the evenness and elasticity, may operate 

 in a similar way. With all the care taken by barrel- 

 makers, in the manufacture of the choicest and highest- 

 priced guns, they well know how difficult it is to get 

 them of true and even proportions and weight. 



Again, barrel-makers find serious difficulty in making 

 the tube perfectly straight and true inside. Although 

 their accurate and accustomed eyes can usually tell if 

 there is much inequality, they often find, by introdu- 

 cing a close-fitting iron plug with a piston-rod attached, 

 that there is an obstruction in some part of the pas- 

 sage. Any obstruction or inequality, however slight, 

 hinders the free discharge of the shot or bullet 

 from the gun, and causes proportionately just so 

 much recoil, detracting from the force of the shot 

 and the evenness of the shooting. 



Foulness is one chief cause of the excessive kicking 

 of many guns ; and this can be easily accounted for, 

 since the barrels become lined with dirt from the many 

 discharges of the gun, as all experienced sportsmen 

 know. It is especially to be noticed in duck-shooting. 

 After some twenty shots have been fired from one 

 barrel, with equal quantities of powder, the gun 

 recoils much more violently than at first. On this 

 account many sportsmen reduce the charge of powder 



