Air gun with a quick-releasing device

An air gun with a quick-releasing device comprising:

• a body (10) adapted to control gas flowing through the air gun;
• a head tube (20) attached to a front of the body (10) and having a distal end, and the quick-releasing device mounted on the distal end of the head tube (20), wherein the quick-releasing device comprises:
• a slit (22) vertically defined in the distal end of the head tube (20) to communicate with an inner space of the head tube (20);
• a locking sheet (24) movably received inside the slit (22) to partially enter the inner space of the head tube (20);
• and
• a locking lever (26) with a recoiling spring pivotally mounted on the head tube (20) and having a tongue penetrating the locking sheet (24), wherein the recoiling spring keeps the locking lever (26) pressing the locking sheet (24) down to enter the inner space of the head tube (20);
• and
• a detachably functional tip (30) attached to the head tube and secured by engaging with the locking sheet of the quick-releasing device.