54 THE COMPLETE SHOT 



pull. The true and now always accepted cause was as the 

 author had stated it to be namely, that the recoil jumped 

 the trigger away from the ringer in spite of the muscular 

 contraction that still continued after the let off of the first 

 barrel ; that this muscular contraction continued to act and 

 again caught up the trigger, as soon as the pace of recoil was 

 diminished by the added weight of the shoulder, and so the 

 finger inflicted a heavier blow or pull on the trigger than in 

 the first pull off. In the first pull it was finger pressure, in 

 the next it was pressure acting over distance, and was 

 measurable in foot-pounds, as work or energy is measured. 

 This proved to be the correct solution. 



Consequently, a good single trigger is one that prevents this 

 finger blow from discharging the second barrel. It is 

 impossible to prevent the blow itself, but quite easy to prevent 

 it letting off the second lock. There are at least three principles 

 employed for doing this. 



The first is called the three-pull system ; it is based on 

 the necessity of either the voluntary second pull, or involuntary 

 blow (as the gun may be loaded or unloaded), for intercepting 

 the trigger connection which the subsequent release of the 

 trigger allows a spring to place in readiness to receive the third 

 trigger pull, and act on the second tumbler ; this pull in the 

 unloaded gun is observed to be a third pull, and in the loaded 

 one is only observable as a second pull, because the second has 

 been given involuntarily, and not consciously. 



The double-pull actions are different in principle. Most of 

 them are based upon a lengthening of the time between the 

 first let off and the connections with the second lock coming 

 into position for contact with the trigger. In other words, 

 they are time movements, based upon the knowledge that 

 the second pull, or impact of trigger and finger, came very 

 quickly, and that to delay the intermediate connecting link 

 between trigger and second lock until after this unconscious 

 impact rendered it inoperative. 



A third system is somewhat different, but is also a timer 

 action. It is based upon having a loose or nearly loose piece, 



