A serpentine holding match is kept at a lifted position by means of a spring, and the serpentine is slowly brought to the flashpan as the trigger is pulled, and the fire on the match contacts with the priming powder in the pan to make an explosion.
これは逆にばねの力で火縄を装着した火挟みを常に上がった状態にもどす反発力がかかっており、引金を引くと引いた速度に連動してゆっくりと火挟みが火皿に降り、火縄の火が火皿の火薬に触れて撃発する。