general truth of this conclusion. Exceptions are, however, 

 occasionally met with. 



We have known cases in which, ov/ing to large cham- 

 bers, loose loading, or sluggishly burning powder, the 

 velocity with 1| oz. shot was higher than with 1 oz., 

 although the powder charge and turnover, etc., were the 

 same in both cases. On this point, also, it is not safe to 

 establish a rule on a single exceptional case. Stated 

 generally, we find that in cylinder barrels, the smaller sizes 

 of shot give rather lower velocities measured over 10 

 yards, rather higher pressures and, curiously enough, 

 rather higher recoil than the larger sizes. 



In the choke barrel the difference between large and 

 small shot, although appreciable, is less than in cylinder 

 barrels, but in nearly every case the choke velocities are 

 higher than the cylinders when measured over a range of 

 1 yards. This, we think, is quite in agreement with theory. 



We consider that the action of the choke on the charge 

 of shot is as follows : 



The length of a charge of shot in passing from the 

 diameter of the barrel '729" to the diameter of the 

 choke, say *700", is increased about 8^, so that if the 

 wad behind the shot is kept moving with the same 

 velocity, the front of the charge is accelerated so that its 

 velocity is increased approximately S% in passing from 

 the larger to the smaller diameter, whilst intermediate 

 portions of the charge increase their velocity in propor- 

 tion to their distance from the wad behind them. In 

 actual practice the wad behind the shot probably does 

 not maintain its velocity. It is more reasonable to assume 

 that the average velocity of the shot charge remains 



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